Acrylic
A plastic derived from acrylic acid. It is stronger and lighter than glass and uses for this product are numerous.
Agate
A variety of chalcedony where successive layers of colour are banded in curved or irregular patterns. Frequently dyed for commercial use in jewellery. I use black, blue lace (soft baby blue), black line (black with lines and streaks), and moss agate (dappled pale green) in my designs. Occasionally other altered shades may appear in my work and will be specified.
Amber
A fossil resin of trees that lived tens of millions of years ago. Amber may contain remnants of insects and plants and colours range from transparent to translucent to semi-opaque, yellow, brown, red, black and rarely green and blue. Frequent enhancements include dyeing, heating, clarification and reconstruction with or without the addition of the aforementioned remnants. Copal is also a common substitute as is 'beeswax amber', a processed beeswax from Tibet.
Amazonite
Opaque to translucent microcline (feldspar mineral) in shades of pale green to green-blue.
Amethyst
Purple/violet variety of quartz. Colours can range from very pale to fine and deep. Green amethyst, also known as prasiolite, can occur naturally but most product on the market is obtained artificially by heating amethyst. Chevron Amethyst is characterised by bands of white quartz.
Ametrine
Mixture of amethyst and citrine with zones of purple and yellow. The colour of the zones visible within the gem are due to differing oxidation states of the iron within the crystal. The varying oxidation states are due to there being a temperature gradient across the crystal as it forms. Much of what is on the market has been created by differential heat treatment of amethyst.
Annealing
A process by which metal and glass are treated with heat in order to change their properties. High temperatures, followed by slow cooling aid the strength and durability of glass and the ductility and strength of metal.
Anodizing
Passing of electric current through a metal creating a 'self coat' in a variety of colours. The resultant colour depends on the amount of current running through the piece.
Aquamarine
Variety of beryl ranging from a pale blue, light blue-green or even light green.
Art Deco
An international design movement affecting architecture, interior and industrial design, fashion, art and jewellery introduced by a collective group of French artists, 'La Societé des Arts Décorateurs' in 1900. Initially called 'Style Moderne', the term 'Art Deco' was not coined until the late 1960s in reference to the International Exhibition of Decorative Art (Art Décoratif) of 1925. Popular in Europe in the 1920s and continuing strongly in the USA to the 1930s. Jewellery designs focused on bold colours and geometric shapes. Platinum was the new luxury metal and combined with colourful opaque stones such as lapis lazuli, onyx, jade, and coral. Diamonds, especially pavé-set, emeralds, rubies and sapphires were used in designs with little regard to cost. Costume jewellery was bold and outrageous with Bakelite making a noteworthy appearance.
Art Moderne
A late branch of Art Deco, also known as 'Streamline Moderne'. Curving forms, long horizontal lines and nautical elements in architecture. Jewellery became bold and lavish with tailored styles. Large chunky bracelets, charms, poodle and Christmas Tree pins, rhinestones, jade, opal, citrine and topaz.
Art Nouveau
Art Nouveau (new art) began in France during the Belle Epoque (beautiful era) period from 1880-1915. The Art Nouveau movement featured heavily on themes from nature, fantasy and the female form. Sensual flowing shapes, lines, curves and tendrils along with exotic motifs of flowers, animals, birds, butterflies, dragonflies, peacocks, fairies, mermaids and nymphs were incorporated into wonderful designs. Plique-à-jour enamelling (open back) was popular along with semi precious non faceted cabochon cut gemstones such as opal and moonstone. Pearls and horn were also widely used. Japanese art is of particular note and influence in French Art Nouveau jewellery.
Aurora Borealis
Shortened to AB, this is a metallic oxide finish applied to crystal beads and occasionally glass to give off rainbow like reflections. It was developed by Swarovski in combination with Christian Dior in 1955. Usually applied to one side of the bead so the colours can bounce through the entire bead, however in cases where two sides are coated, the description becomes ABx2.
Aventurine
A metamorphic rock, quartzite, which contains crystals of other minerals, usually green mica. Shades range from a greenish off-white, greyish white to occasionally a bright green.
Azotic®/Aurora® Treatments
Azotic Coating Technology Inc produces a patented enhancing process in which metallic, oxide or nitrate films are applied to many non-porous materials. Topaz and Quartz are the most common gems to receive these treatments and are often referred to as 'Mystic' gemstones. Colours are vivid and electrifying.
Aurora Crystals, also developed by Azotic Coating Technology Inc, are produced by bonding titanium to quartz. The brilliant colour effect obtained is named after the Aurora Borealis and the result is due to optical interference produced by layers of titania.
Care should be taken with jewellery featuring the above treated gemstones as the surface coatings may be scratched. Also be aware of inferior 'copycat' treatments.
Azurite
Blue opaque mineral often associated with copper and frequently found combined with malachite.
Bakelite
Introduced in 1907, Bakelite was the first completely synthetic thermoset plastic. Made primarily from phenol formaldehyde and fillers, it was a practically indestructible moldable material initially for electrical components, telephones and other objects that required heat resistance and durability. Eventually other colours were introduced from the original dark brownish black. When the patents ran out in 1927, American Catalin Corporation and the Marblette Corporation became the principal rivals and Bakelite jewellery became very popular. From the 1930s and into the 1950s Bakelite designs became intricate, but by the end of this period popularity waned. Although initially inexpensive, production lines were being used to manufacture other items and the hand-made methods employed for Bakelite became impractical. Bakelite's moment was over. Today it is highly collectable with prices continuing to move forward.
Beryl
An important gem group, beryllium aluminium silicate. Trace elements create the many colours and varieties - of note are; emerald, aquamarine, heliodore (golden/yellow), morganite (pink), goshenite (clear) and the rare red beryl.
Blackstone
A trade name for a variety of stones, frequently jasper, dyed black and used in jewellery.
Brass/Bronze
Brass is an alloy of copper and zinc, while bronze is an alloy of copper and tin.
Carnival Glass
A pressed glass with an iridescent surface finish created with metallic salts and then re-fired. Inspired by Tiffany and Steuben art glass, most of the homeware line of functional and ornamental objects was made between 1907-1925. It was inexpensive and found in a wide variety of colours. However popularity declined and prices fell where it was frequently used as carnival prizes and giveaway items. Today many of these discarded pieces have become sought after. Carnival glass beads generally have a body of dark blue/black with bright peacock flashes of colour in greens, pinks, amethyst, golds and blues. Necklaces and beads were popular in the 1930s-1950s and are of value as vintage pieces.
Chalcedony
Fine grained quartz with a fibrous microstructure. Naturally blue-whitish grey in colour. Agates, onyx, jasper and chrysoprase are all varieties of chalcedony.
Charoite
Found only in Russia, along the Chara River in Eastern Siberia, this opaque silicate mineral is mainly in shades of deep violet to lilac. Other minerals in association such as orange tinaksite and/or dark aegirine-augite can present veins of additional colour in the main purple body.
Chatoyancy/Chatoyance
Optical reflectance effect seen in certain gemstones. This cat's eye appearance arises from the fibrous structure, inclusions or cavities within a stone. Gemstone species famous for this phenomenon include quartz (notably tiger's eye), moonstone, chrysoberyl, tourmaline to name a few.
Cherry Brand Glass Beads
Glass beads hand made in Japan during the USA occupation of 1945-1952. Many Japanese were living frugally and needed to earn money to survive, and so began the production of these beads. Mostly exported to the USA. Also known as 'Made In Occupied Japan' or 'Sakura Brand'.
Chrysoprase
A highly prized variety of chalcedony occurring in shades ranging from pale to rich and fine translucent apple-green. Opaque varieties with included streaks of other minerals also occur but the value is somewhat reduced. Australia is the primary producer and chrysoprase is sometimes given the name of 'Australian jade', especially in Asia.
Citrine
Variety of quartz with colours ranging from a pale golden yellow through to stronger shades of honey. It is sometimes created by heating amethyst.
Colour Change Gemstones
A colour change gemstone is one that changes from one colour to another depending on the light source. This phenomenon may be subtle or dramatic and is due to the atomic structure of the stone. UV rays in sunlight or flourescent light excite the atoms and create the colour change (artificial light does not). Sapphire and Alexandrite are the most well known in this group.
Components
Rolled gold is the same as gold filled except the layer of gold is thinner.
Gold Plate has a deposit of gold electro-plated onto a base metal. Will wear off with time.
Vermeil is gold plated sterling silver.
Gilding/Gilt is a very thin film of gold on a metal.
Copal
A type of resin produced from plant sap. It is not fossilised, as in the case of amber, but rather an immature recent resin 1000 to 100 years old. Frequently misrepresented as amber.
Cornelian/Carnelian
Chalcedony in varying shades of red.
Corundum
An aluminium oxide to which ruby and sapphire belong.
Costume Jewellery
Costume jewellery has been part of culture since ancient civilizations although the term was not coined until the 1920s. The real golden era for costume jewellery, however, began in the middle of the twentieth century with the production of high quality paste, glass and imitation gemstones with improved cutting and setting techniques. The class structure was changing, so women in all social stations, even working-class, could own a piece of affordable yet stylish jewellery to complement a special outfit and 'costume' jewellery became fashionable. Costume jewellery was further made popular by various designers such as Chanel, Dior & Schiaparelli, however it was the influence of Hollywood and excellent American manufacturing that brought this jewellery to the forefront. These were prolific times enhanced by endorsements from the leading female stars of the '30s ,'40s and '50s who often wore the pieces produced by a range of designers (restrictions in manufacturing during WWII must be noted). In 1955 costume jewellery designs were classified as 'works of art' by a US Federal judge and were accorded the protection of copyright laws. Another decade followed but by the 1970s interest faded in costume jewellery. Most companies from this era are no longer in production or have been taken over by larger corporations and if jewellery is still being produced it is of generally inferior quality and is made in China.NB: Many design and manufacturing houses did not sign or stamp their work as they often created pieces for several companies, relied on their style as a 'signature' or provided a tag or card only attached to the jewellery (with time these have long since vanished).Today there is a substantial secondary market for vintage fashion jewellery and in many instances it has achieved 'collectable' status, increasing in value every year.Most of the vintage costume pieces I feature in my work have been sourced from specialist dealers mainly in the US and UK, many of whom are experts in the field & have consulted on various publications on costume jewellery. Others I find on my travels, however all are selected simply for their beauty & extravagance.
Crystal
Generally glass which contains lead, although the definition can vary from country to country. According to EU rules, glass containing less than 4% lead is defined as 'glass', whereas in the USA it is only 1%. Fully leaded crystal contains at least 24% lead oxide and 'highly leaded' crystal has a minimum of 30%. The presence of lead softens the glass and makes it more accessible for cutting and engraving. It also increases the weight and causes more brilliant light diffraction.
Cubic Zirconia
A cubic form of zirconium oxide (extremely rare in nature) which is created in a laboratory. In the 1970s Soviet scientists perfected the technique for growing the crystals for use primarily in laser technology. In the 1980s Swarovski began mass producing cubic zirconia, it is hard and optically flawless and its use in jewellery became established. A frequently used diamond substitute, it is combined with yttrium oxide and can also be coloured with various other oxides.
Diamond
Transparent crystal of tetrahedrally bonded carbon atoms. The hardest natural material known due to the chemical bonds which form an inflexible three dimensional lattice.
Impurities such as nitrogen, irradiation and plastic deformation (non-reversible change of shape in response to applied force) can colour diamonds as can enhancements such as heating and/or applied irradiation.
The perfect diamond containing no impurities is colourless but in reality most are coloured, with brown and yellow the most common. Pink, orange, green, grey, blue, voilet and red (rarest) are seldom found, sometimes fewer than one in ten thousand. Black 'Carbonado' diamonds contain numerous dark inclusions.
Development and production of synthetic diamonds began in the mid twentieth century, however the growing techniques and processing complications initially rendered them too expensive. New technology has since been developed reducing the cost and allowing for the advancement of commercially viable synthetic diamond production, in particular fancy coloured stones.
Dumorterite
Fibrous crystal often associated with quartz. Commonly greyish blue, denim blue, green-blue but also occurring in violet-reddish purple and brown.
Enamel
A decorative technique in which powdered glass paste is fused onto a metal.
Enhancements/Treatments
Many gemstones are routinely enhanced by various methods in order to improve appearance, durability, appeal, value and availability. This widespread practice includes procedures such as bleaching, dyeing, irradiation, heating, lasering, filling and diffusion - to name a few. Therefore some gemstones used in my creations may have been treated as per the accepted standard in the gemstone industry for that particular variety. I do not use any assembled or imitation gemstones. Any synthetic (manmade) stones will be disclosed in the item description.
Feldspar
A class of aluminium containing silicates which are the most abundant minerals on earth. Feldspathoids resemble Feldspars but have a different structure and much lower silica content.
Fossilisation
The term 'fossil' describes a wide range of natural artifacts. Generally speaking, a fossil is any evidence of past plant or animal life that is preserved in the material of the earth's crust. In most cases, the fossilisation process began when a plant or animal died and was quickly covered with sediments, usually at the bottom of a body of water. The loose sediments protected the bodily remains from the elements, bacteria and other forces that cause weathering and decay. This slowed the decaying process so that some of the remains (in most cases only hard material like bone or shell) were preserved for thousands of years. During this time, sediment layers continued to collect and eventually these sediment layers became hard, solid rock. This process ranges from thousands of years to many millions of years ago. The earliest fossils of complex life date from around 600,000,000 years with recent reports of bacteria revealing up to 3 billion years earlier.
Fluorite
Fine transparent crystal in a range of colours including colourless, yellow, brown, green, blue, violet, pink. Also available in banded varieties of white/blue/violet/purple.
Galalith
Sometimes referred to as French Bakelite, an early plastic made from the natural milk protein, casein. Combined with formaldehyde it was initially developed in 1899, but it took some time to perfect the recipe. It was an easy material to colour and was made to imitate natural materials such as pearls and tortoiseshell and found its niche in buttons, beads, pen barrels and jewellery components. Galalith was also known under several other trade names and found success primarily in Europe. Production ceased mainly in the 1960s with the final British producer stopping manufacture in about 1980.
Garnet
A large family of related silicate minerals, some of which are gemstones. Six common species of garnet are recognised based on their chemical composition. They are pyrope, almandine, spessartite, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. Colours include various shades of red, pinkish red, burgundy, grape, orange, gooseberry, honey yellow/brown, green, black, colourless and the extremely rare blue.
Gaspéite
A rare, bright green, nickel magnesium iron carbonate material named after the place in which it was first discovered, the Gaspé Peninsula, Quebec, Canada in 1966. The best gem quality however, comes from south of Kalgoorlie in Western Australia. It is unearthed during nickel mining and was originally stockpiled for later treatment to remove the nickel ore. For various reasons the stockpiles were abandoned and were sold in 1997 to an American gemstone dealer. Further nickel mining operations have now buried much of this remaining Gaspéite so very little now comes on to the market.
Glass Beads
Vintage glass beads, including crystal, are used in some of my designs. Czechoslovakia, Italy, West Germany and Japan were the prolific and innovative producers each offering different styles. With the onset of World War 2, especially in Europe, the glass industry took a heavy blow as many producers were Jewish. Many factories were shut down as a consequence and were never re-opened. European beads pre-dating the 1940s are highly collectable and have a unique quality and beauty. In the 1960s jewellery fashions went through many changes. Glass beads were expensive and more plastics were being used to cut costs. Several jewellery manufacturers ceased to trade leaving warehouses of unused beads which have been rediscovered and given new life especially in my work. Today's mass produced beads from India and China are considered by many to be inferior.
Gold
Here I have listed the metals added to gold to change its colour (NB: an alloy is a mixture of two or more metallic elements).
Goldstone
Not actually a gemstone but a type of glass made with copper or copper salts and sometimes cobalt, manganese or chromium. The manufacturing process dates back to the 17th century in Venice and was highly guarded at the time. The most common form of Goldstone is reddish brown containing tiny crystals of metallic copper. Cobalt and manganese substitution results in a product with a more silvery appearance suspended in a strongly coloured matrix known as blue or purple Goldstone. Green Goldstone forms its reflective particles from chromium oxides.
Greenstone (Pounamu)
New Zealand greenstone is a variety of nephrite jade found mainly on the west coast of the South Island. Highly prized by the Maori for weapons, tools and jewellery, export of raw material was made illegal in 1947. Sadly today much of what is sold in New Zealand is in fact Chinese jade.
Hematine
The man made form of haematite (iron oxide). A dark blackish grey with a metallic sheen. Most products on the market today labelled 'haematite' are in fact not natural. The man made variety is considered superior for use in jewellery as it does not rust and is not brittle. Only the man made form can be magnetised and is believed by some to ease joint/arthritic pain. 'Hemalyke' is another trade mark name for this product.
Herkimer Diamonds
Actually not a diamond but a double-terminated quartz found in Herkimer County, New York, and surrounding areas. These quartz crystals grow slowly in vugs (pockets) with very little or no contact with their host rock. They have 18 natural facets, two terminations (points) and can be found clear, cloudy or with a variety of general or rare impurities. Designs featuring wire-wrapping of the crystal are the most prevalent but crystals cut from larger specimens, can be given extra faceting and set into rings etc.
Howlite
A white mineral, calcium borosilicate hydroxide featuring streaks of grey-black. It is frequently dyed and sometimes used to imitate turquoise.
Hypersthene
Magnesium iron silicate, mostly deep brown but also green and grey. Displays a beautiful copper-red schiller.
Igneous Rock
One of the three rock types. It is formed by magma (molten rock) which has cooled and solidified.
Iolite
Sometimes referred to as cordierite or water sapphire, this magnesium aluminium silicate ranges from transparent shades of sapphire blue to blue/violet to yellowish grey to light blue depending on the angle of light as it hits the stone.
Jade
Comprising two distinct minerals, jadeite and nephrite. Occurs in a range of colours including pale to dark green and almost black, white, lilac, grey, blue/green. Jadeite, also known as Chinese jade, is the most valuable.
Jasper
A variety of quartz frequently containing significant amounts of other materials. Commonly dark brownish red, yellow, black, it also features many variegated and banded types. Patterns abound creating many different forms with individual names such as rainforest, ocean, leopard, and network.
Jet
Fossilised wood (type of coal/lignite) from an ancient tree similar to the araucaria or monkey puzzle tree which flourished during the Jurassic period more than 180 million years ago. Whitby, on the Yorkshire coast of England, is the most famous location for top quality jet. It became extremely popular as mourning jewellery during the reign of Queen Victoria after the death of her beloved Prince Albert in 1861. Spanish jet of a lesser grade was also widely used as supplies in Whitby could barely meet the strong demand. Today production of Whitby jet is extremely limited as only that which is washed ashore may be used (mining over the years has led to severe erosion and is now prohibited). Antique pieces fetching increasingly high prices. Please note: French jet is a black glass substitute popular in the late 1800s-1920s.
Karen Silver
Silver produced by the Karen Hillside tribes of Northern Thailand containing 97- 99% pure silver (sterling silver is 92.5% pure). All components are handmade. These communities are members of Fairtrade, and work hard to maintain their culture and craft. The silver is a whiter shade than sterling and does not tarnish easily. I feature beads and clasps in some of my designs. Of particular interest is the range of black silver, actually a lovely shade of gunmetal grey, they produce.
Kyanite
Blue to blue/green silicate mineral with a pearly lustre. It is frequently zoned and with pleochroism near colourless, violet/cobalt blue or different shades of green.
Labradorite
A feldspar with a ground colour of dark smoke grey, but when light strikes in a particular direction, it displays striking rainbow-coloured metallic reflections, or schiller. This is referred to genarally as labradorescence and is mainly caused by the interference of light from lattice distortions, cracks or structural layers breaking up light into special colours. Spectrolite is the vivid coloured variety from Finland and also India.
Lacquer
Lacquer is made from the sap of the Lac tree (Rhus Verniciflua). It has been used for thousands of years both for objects of beauty and for utensils of a practical nature. Many layers are required and each layer must dry for several days before the next can be applied. Cinnabar is a precious pigment which creates the Imperial Red colour used throughtout Asia.
Lapis Lazuli
A rock containing an association of minerals with the main constituent being lazurite (a feldspathoid) in opaque or semi-opaque shades of blue. Patches and veins are common in grey and off-white, as are scattered crystals of gold pyrite.
Larvikite
A greyish blue rock frequently likened to granite. It displays a pearl-grey iridescence, opalescence or even labradorescence on its surface due to the presence of handsom crystals of feldspar. In the past was sometimes used in building construction - notably in Chicago and in the UK.
Lava Stone
Igneous rock (produced from volcanic eruptions). It is usually treated with wax or resing to smooth the abrasive texture. Naturally a greyish black with a porous texture.
Lucite
Lucite is the brand name of a polyacrylic developed by DuPont in 1931. A similar formula called Plexiglass, also known as Perspex was developed around the same time. It combines the properties of both plastic and glass and is approximately 8 times clearer than glass. After World War II Lucite became popular for use in jewellery and today vintage acrylics are in high demand. Lucite and its similar competitors are still being made, but DuPont sold the operations to a UK company in 1993.
Malachite
Distinctive veins and bands of green in various shades identify this mineral. It frequently occurs with blue azurite and is then called azurite-malachite.
Marcasite
A polymorph (different structure) of iron sulphide or white iron pyrite. It has an unstable crystal structure and frequently crumbles. What is used in jewellery and labelled 'marcasite' is actually pyrite. Marcasite jewellery was popular in England as an affordable diamond substitute during the mid-late 18th century (particularly after the death of Prince Albert in 1854) when 'mourning jewellery' was fashionable. Demand continued until the end of the Art Deco period.
Matrix Rock
The host rock in which a mineral specimen is found.
Metamorphic Rock
One of three rock types. It is formed when either igneous, sedimentary or other metamorphic rock is altered by heat, pressure or chemical process.
Mineral vs Rock
Simply put, a mineral is a naturally occurring solid with a definite chemical composition and a specific crystalline structure while a rock is an aggregate of two or more mineral constituents.
Moissanite
Trade name given to silicon carbide and used as a diasmond simulant. History can be traced back to 1893 when Dr Henry Moissan discovered minute mineral quantities of silicon carbide in an ancient meteorite in Diablo Canyon, Arizona. It can be grown in a lab and was used by scientists in the 1960s and 1970s for various applications, but it was not until the 1980s that a proprietory process was developed for producing large single crystals of moissanite. One company has the exclusive manufacturing and marketing rights and in 1998 moissanite jewellery was launched. Moissanite does not grade well on the GIA diamond colour scale, merely an I/J. However, perfect cutting of these stones, very high level of fire and brilliance (exceeding that of diamond) raises the colour perception to white. NB: variation does occur with different cuts, the brilliant is optimal. Poor lighting can affect the brilliance and fire leading to a greenish tinge of the stone. Currently moissanite can be manufactured in clear, green, yellow and blue and is approximately 0ne eighth the price of a diamond.
Moldavite
A type of tektite (solidified splashes of rock melted by the impact of a meteorite than hardening in the air approximately 15 million years ago). It is glass-like and occurs in olive/bottle green transparent-translucent shades. Discovered along the Moldau River Valley in Bohemia and Monrovia, Czechoslavakia. There are now only four active mines and commercial supply may soon be exhausted.
Moonstone
The most common moonstone is of the mineral adularia, a member of the feldspar group. It is characterised by a milky white to bluish shimmering sheen effect across the top of the stone as it is turned and moved (adularescence). Moonstone is also a variety name and not just confined to this one single species. Body colours can range from colourless to grey, brown, yellow, pale orange/peach, green, plum-blue, reddish or pink.
Nautilus
Nautilus is the common name for any marine creature from the cephalopod family nautiidai which has survived for more than 450 million years. It is often referred to as a 'living fossil'. The shell is lined with Mother of Pearl and grows increasingly larger chambers (up to 30) throughout its lifespan of up to 20 years. This noctural creature is found near reefs in the depths of the Indian and Pacific Oceans. But for feeding, mating and laying eggs, it surfaces to shallower water. Taking 5 - 10 years to mature, numbers are decreasing and although some countries have banned sale of their shell, it is not yet listed on CITES (Convention on International Trade for Endangered Species). Whole Nautilus shells were popular display items in the mid-1800 Victorian times, and shells sliced down the centre are used for jewellery.
Niobium
Stable hypo-allergenic metal which can be anodized into various colours.
Obsidian
Volcanic glass formed by rapid cooling of lava. Normally opaque black or grey, it may also be yellow, red, greenish brown and rarely blue. Rainbow obsidian has an iridescent sheen. Mahogany obsidian has brownish/red and black bands. Snowflake obsidian has inclusions of white.
Onyx
A variety of chalcedony similar to agate however the successive bands of colour are parallel. Dyed black for commercial use in jewellery. Sardonyx is the variety with white and black/brown bands.
Opal
A mineraloid gel (mineral-like substance that does not display crystallinity) with a water content usually 3% - 10%, but sometimes as high as 20%. Occurs in the fissures of almost any kind of rock and shades include white, grey, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, black.
Opalite
Man made opal imitation comprising layered glass or resin with a metal oxide between the layers displaying a milky bluish white translucence.
Palladium
Lustrous silvery white metal belonging to the Platinum group metals.
Pearls
China produces most of the freshwater pearls on the market today and they are the primary type I use in my designs. Cultured and mostly non nucleated, they come in a myriad fanciful shapes and exotic colours. Freshwater pearls today are of superior quality due to changing the type of mussel in the mid 1990s and reducing the number of grafts from 50 down to 24-32. They are harvested between 2 - 6 years, significantly longer than the 6 - 9 months in the 1980s. Rounder and larger nucleated pearls are now also being produced and surface finishes such as faceting are becoming popular. The process of nucleation is easier in freshwater pearls with only mantle tissue being used. This tissue eventually dissolves resulting in solid nacre pearls. Receding can occur up to three times, although subsequent pearls are flatter but colour and lustre may be stronger. Natural colours of freshwater pearls include orange, lavender, pink, cream and enhancements usually involve dyeing and/or irradiation, bleaching or whitening with fluorescent brightening agents and tumble polishing. Mussel hybridisation has also led to the exotic array of colours. (All 'Black' freshwater pearls have been dyed.)
Freshwater pearls are also cultivated in Eastern Central USA, especially the Tennessee River. Shell beads used in saltwater pearl nucleation come from the mussels living in this river. Unlike Chinese and Japanese freshwater pearls, American freshwater pearls are bead nucleated and are grown for up to five years producing a superior and more expensive pearl featuring sticks, crosses and wildly shaped baroques . It is the only type of pearl which is not routinely enhanced.
Saltwater pearls have both a bead and mantle tissue nucleation process and are more susceptible to environmental conditions.
Peridot
Shades ranging from olive to bottle and bright green. It belongs to the mineral group olivine (magnesium iron silicate).
Pewter
Eighy five to ninety per cent tin, with the remainder consisting of copper, bismuth, antimony and in lower grades, lead.
Pietersite
A variety of quartz with fibrous bands of blue, gold and/red tiger's eye. It displays a gentle chatoyancy with the aforementioned colours.
Pleochroism
Optical phenomenon in which gems or crystal appear to be different colours when observed at different angles. Two colours/shades - dichroic, three colours/shades - trichroic.
Polymer
A large molecule composing many repeating structural units connected by chemical bonds. Plastics are a well known polymer and natural polymers include shellac and amber.
Pyrite
Iron sulphide in a metallic yellow colour ranging from pale to brassy. It earned the name 'fools gold' due to its initial similarity to the appearance of gold.
Quartz
One of the most widely distributed minerals in the earth's crust. Occurring in several colours including clear (also known as rock crystal), milky, lemon, rose, smokey, purple (amethyst), yellow (citrine), green (prasiolite or green amethyst). Blue is extremely rare and most on the market is a synthetic product. Quartz with gold needle like inclusions is named rutilated quartz and quartz with black needles of tourmaline is tourmalinated quartz.
Resin
Common name for a class of casting polymers typically requiring two parts. When the parts are mixed they fuse via a chemical reaction resulting in a type of plastic.
Retro Period
1935-1949, here designers struggled with art versus mass production. Natural elements merged with plastics. Many European jewellery firms were shut down due to WWII and several designers emigrated to the USA. The'American' style was glamourous, elegant and sophisticated with a Hollywood flair featuring flowers, bows, ballerinas, sunbursts, moonstones, horse and military motifs. 'Cocktail' rings, often with semi-precious stones such as aquamarine, topaz and synthetics up to 100 carats and the use of rose gold replacing platinum of the Deco era.
Rhinestones
Originally quartz crystals gethered from the Rhine River. This natural source has long since been depleted and Rhinestones are now generally made from glass. On vintage pieces Rhinestones are often referred to as 'paste'. Glass was ground into an actual paste and then moulded and mounted into shape. These manufactured stones had many air bubbles, but these were counteracted by the high lead contect of the glass, faceting, and a backing of metallic paint. The best quality crystal rhinestones are produced mainly in Austria by Swarovski and in the Czech Republic by Preciosa and a few other Bohemian glassworks in Northern Bohemia.
Rhodium
A rare silvery white metal, member of the platinum group and the most expensive precious metal used in jewellery. It is extremely reflective and provides a corrosion and tarnish resistant finish when electro-plated onto other metals.
Rhodonite
A manganese inosilicate occurring in transparent to translucent rose pink to brownish red frequently with black veins running through it.
Roman Glass
Roman Glass is the general term applied to ancient glass made within the vast Roman Empire dating as far back as the 1st century BC. (Glass was invented around 2200 BC in what is now North Western Iran). However, it was not until the 1st Century AD that interest was shown and glass-working became an industry, as opposed to a craft. Ancient Israel was one of the largest glass producers in the Roman Empire and many glass remnants have been unearthed during archaeological digs in the Judean Desert and other Mediterranean countries. Fragments and pieces set into jewellery are broken parts of what were once household items such as vases and drinking vessels, mainly for the wealthy. As manufacturing techniques improved, rapid production enabled its use to become more widespread and available to the general population. Aqua is the common natural colour of untreated glass and after centuries of preservation in the sand, weathered and unusual textures have made every piece unique.
Ruby-Zoisite
Also known as anyolite, a natural combination of ruby and zoisite in a single specimen. Zoisite provides the earthy green and black colour while ruby lends red and pink.
Ruthenium
A member of the Platinum Group Metals, an extremely hard metal used as an alloy for palladium and platinum and also as a surface coating. The colour may be modified from light to dark grey shades.
Sapphire
Variety of corundum occurring in almost every shade except red, whereby the stone is called 'ruby'.
Schiller
Optical phenomenon where a play of colour occurs on the surface of some gemstones. Labradorite, with its flashes of iridescent colour (labradorescence), and moonstone (adularescence) are among the most well known.
Sea Bamboo/Coral
The term 'Coral' refers to a vast array of calcium carbonate secreting marine organisms which grow in varying structures under water. Sea Bamboo is named for its branch-like appearance and is a readily available form of coral used in jewellery. Generally white with black/brown it is then dyed red. Other varieties of coral naturally occurring in red/pink, black, and golden command very high prices while blue has low value due to its porous nature and inability to polish well (blue coral is mostly used for acquariums). Certain species of coral are listed by CITES (Convention on International Trade on Endangered Species) and are prohibited for sale. Coral is porous and can be impregnated with resin to stabilise the product.
Sedimentary Rock
One of the three rock types. It is formed by deposition or consolidation of mineral and organic material and also by precipitation of minerals from solution.
Selenium Glass
Selenium, a metalloid (element with characteristics of both a metal and non-metal) colours glass pink and red shades.
Seraphinite
Mined in Russia, a member of the chlorite group of minerals in shades of forest green to green/black. Inclusions of silvery mica display a chatoyancy or cat's eye effect.
Sodalite
Typically a light to rich royal blue feldspar frequently with veins or patches of white/grey.
Stainless Steel
Generic word for steel with a minimum chromium content of 10.5%. Other elements may also be present, including nickel. Nickel may cause allergies in some people but this is reduced by the use of surgical or hypo-allergenic stainless steel. However a small percentage of nickel remains (the EU has set the limit at 0.05% and the UK 0.01%).
Sugilite
Pure sugilite is a complex silicate which gets its purple colour from manganese. Most of the more variously coloured material ranging from pink-dark purplish black is a rock composed of both sugilite and chalcedony. When chalcedony is present there are also variable amounts of light and dark mottling.
Swarovski
The undisputed leader in crystal bead production. Daniel Swarovski invented the first automatic cutting machine in 1892 and in 1895 the company was established in Wattens, Austria. He went into business at a time when the arts, literature, music and science were cross-pollinating across central Europe. The company was steeped in culture, innovation and creativity from the outset. During the opening decades of the 20th century, Swarovski crystals became an essential ingredient in the world of high fashion. The company worked with iconic figures such as Chanel, Schiaparelli, Balenciaga and later Dior. Swarovski crystal contains approx 32% lead to maximise refraction and many metallic coatings have been formulated, such as the popular AB. In the 1950s and 1960s competition amongst costume jewellery manufacturers was intense. Swarovski was commissioned to produce exclusive combinations for them and in order to keep the designs secret, numbers were assigned to the beads rather than names. Many companies, however, were unable to survive the high production costs associated with their range and the ability to successfully market the jewellery at an affordable price, so eventually had to close and auction off their inventory. Beautiful vintage Swarovski from the 1950s-1970s in sizes or shapes or colours which are no longer produced are available from specialist dealers and are used in some of my work. I also use components currently available and produced by Swarovski.
Synthetic/Imitation Gemstones
Synthetic Gemstones are made in a laboratory and have the same basic chemical composition and similar chemical, optical and physical properties to its natural counterpart. Ruby was the first commercially grown synthetic stone of the early 1900s. Imitation Gemstones merely imitate the colour and look of natural stone and may be made from anything.
Tiger's Eye
Famous for its chatoyancy, this variety of quartz with fibrous inclusions of crocidolite (asbestos) is banded with gold, yellow and brown. The rarer blue counterpart is named hawk's eye and the mahogany is named bull's eye or ox eye.
Tiger Iron
An altered rock, mainly of tiger's eye, red jasper and haematite in bands of undulating colour.
Titanium
High tech super strong and lightweight metal resistant to corrosion. May be anodized into colours.
Topaz
Silicate mineral of aluninium and fluorine. Pure topaz is colourless and transparent but impurities lead to tints in shades such as wine, yellow, grey, reddish-orange, brown and pink (rare). Treatments including heating and/or irradiation can create several other shades and intensities of colour.
Tourmaline
A silicate mineral group with many elements including aluminium, iron, magnesium, sodium, lithium and potassium. Colours abound and include black, green, pink, blue, red and bi-coloured and multi-coloured varieties.
Turitella Fossil
Calcium carbonate with white to grey to pink fossil inclusions.
Turquoise
Hydrated phosphate of copper and aluminium. The various colours result from copper (vivid blue) and iron (softer greens). The presence of matrix rock in black, brown or yellowish-brown create a vein-like appearance. Turquoise is frequently treated, impregnated with wax or resin to improve colour, hardness or to protect against fading. Persian sky blue/robins egg blue is considered superior with Iranian deposits once the most sought after. However the southwestern area of the USA has a number of mines and is now the largest producer in the world of turquoise. Colours include dark green, bright blue, light blue and veined.
Uranium Glass
Up to 2% uranium salts (uranium dioxide) added to glass creating a vivid green glow when under blacklight or sunlight. Ultra violet radiation excites the outer electrons of the uranium atoms which as a result give off energy and is seen by our eyes as this brilliant glow. Originally used in the production of tableware and decorative household items from the mid 19th century, these antiques and retro-era items have become collectible. The beads I use in my work date to around the 1920s-30s and are becoming extremely scarce. Tight regulations on uranium dioxide and the expense of this ingredient have limited the quantities being produced today. I also have a few treasured pieces where manganese was used as the additive and these beads will glow a fainter green under UV light. Please note the radioactivity of the glass is considered negligible and not harmful.
Venetian Glass
Venetian Glass is primarily made on the island of Murano, across the lagoon from Venice. It is world-renowned for being colourful, elaborate and skillfully made. All Venetian Glass production moved to Murano in the 13th Century to protect Venice from the risk of fires, and to keep the glassmaking techniques a secret. The process of making Murano/Venetian Glass is complex and many techniques developed and guarded from centuries ago are still in use today.
Vintage Beads
My personal classification for these artworks of the past are beads manufactured prior to the 1970s with emphasis on the period from the 1920s-1960s. Please refer to specific headings in this glossary.
Zoisite
Calcium aluminium iron sorosilicate mineral. Tanzanite is the most famous in this group but must be artificially heated to bring out the spectacular blue-violet of the stone.
A plastic derived from acrylic acid. It is stronger and lighter than glass and uses for this product are numerous.
Agate
A variety of chalcedony where successive layers of colour are banded in curved or irregular patterns. Frequently dyed for commercial use in jewellery. I use black, blue lace (soft baby blue), black line (black with lines and streaks), and moss agate (dappled pale green) in my designs. Occasionally other altered shades may appear in my work and will be specified.
Amber
A fossil resin of trees that lived tens of millions of years ago. Amber may contain remnants of insects and plants and colours range from transparent to translucent to semi-opaque, yellow, brown, red, black and rarely green and blue. Frequent enhancements include dyeing, heating, clarification and reconstruction with or without the addition of the aforementioned remnants. Copal is also a common substitute as is 'beeswax amber', a processed beeswax from Tibet.
Amazonite
Opaque to translucent microcline (feldspar mineral) in shades of pale green to green-blue.
Amethyst
Purple/violet variety of quartz. Colours can range from very pale to fine and deep. Green amethyst, also known as prasiolite, can occur naturally but most product on the market is obtained artificially by heating amethyst. Chevron Amethyst is characterised by bands of white quartz.
Ametrine
Mixture of amethyst and citrine with zones of purple and yellow. The colour of the zones visible within the gem are due to differing oxidation states of the iron within the crystal. The varying oxidation states are due to there being a temperature gradient across the crystal as it forms. Much of what is on the market has been created by differential heat treatment of amethyst.
Annealing
A process by which metal and glass are treated with heat in order to change their properties. High temperatures, followed by slow cooling aid the strength and durability of glass and the ductility and strength of metal.
Anodizing
Passing of electric current through a metal creating a 'self coat' in a variety of colours. The resultant colour depends on the amount of current running through the piece.
Aquamarine
Variety of beryl ranging from a pale blue, light blue-green or even light green.
Art Deco
An international design movement affecting architecture, interior and industrial design, fashion, art and jewellery introduced by a collective group of French artists, 'La Societé des Arts Décorateurs' in 1900. Initially called 'Style Moderne', the term 'Art Deco' was not coined until the late 1960s in reference to the International Exhibition of Decorative Art (Art Décoratif) of 1925. Popular in Europe in the 1920s and continuing strongly in the USA to the 1930s. Jewellery designs focused on bold colours and geometric shapes. Platinum was the new luxury metal and combined with colourful opaque stones such as lapis lazuli, onyx, jade, and coral. Diamonds, especially pavé-set, emeralds, rubies and sapphires were used in designs with little regard to cost. Costume jewellery was bold and outrageous with Bakelite making a noteworthy appearance.
Art Moderne
A late branch of Art Deco, also known as 'Streamline Moderne'. Curving forms, long horizontal lines and nautical elements in architecture. Jewellery became bold and lavish with tailored styles. Large chunky bracelets, charms, poodle and Christmas Tree pins, rhinestones, jade, opal, citrine and topaz.
Art Nouveau
Art Nouveau (new art) began in France during the Belle Epoque (beautiful era) period from 1880-1915. The Art Nouveau movement featured heavily on themes from nature, fantasy and the female form. Sensual flowing shapes, lines, curves and tendrils along with exotic motifs of flowers, animals, birds, butterflies, dragonflies, peacocks, fairies, mermaids and nymphs were incorporated into wonderful designs. Plique-à-jour enamelling (open back) was popular along with semi precious non faceted cabochon cut gemstones such as opal and moonstone. Pearls and horn were also widely used. Japanese art is of particular note and influence in French Art Nouveau jewellery.
Aurora Borealis
Shortened to AB, this is a metallic oxide finish applied to crystal beads and occasionally glass to give off rainbow like reflections. It was developed by Swarovski in combination with Christian Dior in 1955. Usually applied to one side of the bead so the colours can bounce through the entire bead, however in cases where two sides are coated, the description becomes ABx2.
Aventurine
A metamorphic rock, quartzite, which contains crystals of other minerals, usually green mica. Shades range from a greenish off-white, greyish white to occasionally a bright green.
Azotic®/Aurora® Treatments
Azotic Coating Technology Inc produces a patented enhancing process in which metallic, oxide or nitrate films are applied to many non-porous materials. Topaz and Quartz are the most common gems to receive these treatments and are often referred to as 'Mystic' gemstones. Colours are vivid and electrifying.
Aurora Crystals, also developed by Azotic Coating Technology Inc, are produced by bonding titanium to quartz. The brilliant colour effect obtained is named after the Aurora Borealis and the result is due to optical interference produced by layers of titania.
Care should be taken with jewellery featuring the above treated gemstones as the surface coatings may be scratched. Also be aware of inferior 'copycat' treatments.
Azurite
Blue opaque mineral often associated with copper and frequently found combined with malachite.
Bakelite
Introduced in 1907, Bakelite was the first completely synthetic thermoset plastic. Made primarily from phenol formaldehyde and fillers, it was a practically indestructible moldable material initially for electrical components, telephones and other objects that required heat resistance and durability. Eventually other colours were introduced from the original dark brownish black. When the patents ran out in 1927, American Catalin Corporation and the Marblette Corporation became the principal rivals and Bakelite jewellery became very popular. From the 1930s and into the 1950s Bakelite designs became intricate, but by the end of this period popularity waned. Although initially inexpensive, production lines were being used to manufacture other items and the hand-made methods employed for Bakelite became impractical. Bakelite's moment was over. Today it is highly collectable with prices continuing to move forward.
Beryl
An important gem group, beryllium aluminium silicate. Trace elements create the many colours and varieties - of note are; emerald, aquamarine, heliodore (golden/yellow), morganite (pink), goshenite (clear) and the rare red beryl.
Blackstone
A trade name for a variety of stones, frequently jasper, dyed black and used in jewellery.
Brass/Bronze
Brass is an alloy of copper and zinc, while bronze is an alloy of copper and tin.
Carnival Glass
A pressed glass with an iridescent surface finish created with metallic salts and then re-fired. Inspired by Tiffany and Steuben art glass, most of the homeware line of functional and ornamental objects was made between 1907-1925. It was inexpensive and found in a wide variety of colours. However popularity declined and prices fell where it was frequently used as carnival prizes and giveaway items. Today many of these discarded pieces have become sought after. Carnival glass beads generally have a body of dark blue/black with bright peacock flashes of colour in greens, pinks, amethyst, golds and blues. Necklaces and beads were popular in the 1930s-1950s and are of value as vintage pieces.
Chalcedony
Fine grained quartz with a fibrous microstructure. Naturally blue-whitish grey in colour. Agates, onyx, jasper and chrysoprase are all varieties of chalcedony.
Charoite
Found only in Russia, along the Chara River in Eastern Siberia, this opaque silicate mineral is mainly in shades of deep violet to lilac. Other minerals in association such as orange tinaksite and/or dark aegirine-augite can present veins of additional colour in the main purple body.
Chatoyancy/Chatoyance
Optical reflectance effect seen in certain gemstones. This cat's eye appearance arises from the fibrous structure, inclusions or cavities within a stone. Gemstone species famous for this phenomenon include quartz (notably tiger's eye), moonstone, chrysoberyl, tourmaline to name a few.
Cherry Brand Glass Beads
Glass beads hand made in Japan during the USA occupation of 1945-1952. Many Japanese were living frugally and needed to earn money to survive, and so began the production of these beads. Mostly exported to the USA. Also known as 'Made In Occupied Japan' or 'Sakura Brand'.
Chrysoprase
A highly prized variety of chalcedony occurring in shades ranging from pale to rich and fine translucent apple-green. Opaque varieties with included streaks of other minerals also occur but the value is somewhat reduced. Australia is the primary producer and chrysoprase is sometimes given the name of 'Australian jade', especially in Asia.
Citrine
Variety of quartz with colours ranging from a pale golden yellow through to stronger shades of honey. It is sometimes created by heating amethyst.
Colour Change Gemstones
A colour change gemstone is one that changes from one colour to another depending on the light source. This phenomenon may be subtle or dramatic and is due to the atomic structure of the stone. UV rays in sunlight or flourescent light excite the atoms and create the colour change (artificial light does not). Sapphire and Alexandrite are the most well known in this group.
Components
- Clasps - Sterling silver, Karen hilltribe silver (99% pure) or nickel plate. It will be specified with each design.
- Ear hooks/wires - Sterling silver , surgical steel and other assorted metal finishes depending on design. It will be specified with each item.
- Stringing - Premium quality wire from the leading US manufacturer used in all work. Up to 49 strands of stainless steel encased in nylon provide superior strength and flexibility.
- Spacers - Tiny beads used between larger ones. They serve to aid movement and draw attention to the main design element/s. Generally Czechoslovakian glass unless otherwise stated.
- Wire Work - Anti-tarnish silver, nickel plate, sterling silver or Argentium . It will be specified with each design. Argentium, the trade mark for sterling silver containing a small amount of germanium. This metalloid replaces a little of the 7.5% copper present in sterling silver. It provides a superior finish, does not become dull and is totally resistant to tarnishing. It is more expensive than standard sterling silver.
- Memory Wire - Tempered Stainless Steel wire which snaps back to its original form when expanded and released.
- Gold - Occasionally gold will be used in my designs and will be specified.
Rolled gold is the same as gold filled except the layer of gold is thinner.
Gold Plate has a deposit of gold electro-plated onto a base metal. Will wear off with time.
Vermeil is gold plated sterling silver.
Gilding/Gilt is a very thin film of gold on a metal.
Copal
A type of resin produced from plant sap. It is not fossilised, as in the case of amber, but rather an immature recent resin 1000 to 100 years old. Frequently misrepresented as amber.
Cornelian/Carnelian
Chalcedony in varying shades of red.
Corundum
An aluminium oxide to which ruby and sapphire belong.
Costume Jewellery
Costume jewellery has been part of culture since ancient civilizations although the term was not coined until the 1920s. The real golden era for costume jewellery, however, began in the middle of the twentieth century with the production of high quality paste, glass and imitation gemstones with improved cutting and setting techniques. The class structure was changing, so women in all social stations, even working-class, could own a piece of affordable yet stylish jewellery to complement a special outfit and 'costume' jewellery became fashionable. Costume jewellery was further made popular by various designers such as Chanel, Dior & Schiaparelli, however it was the influence of Hollywood and excellent American manufacturing that brought this jewellery to the forefront. These were prolific times enhanced by endorsements from the leading female stars of the '30s ,'40s and '50s who often wore the pieces produced by a range of designers (restrictions in manufacturing during WWII must be noted). In 1955 costume jewellery designs were classified as 'works of art' by a US Federal judge and were accorded the protection of copyright laws. Another decade followed but by the 1970s interest faded in costume jewellery. Most companies from this era are no longer in production or have been taken over by larger corporations and if jewellery is still being produced it is of generally inferior quality and is made in China.NB: Many design and manufacturing houses did not sign or stamp their work as they often created pieces for several companies, relied on their style as a 'signature' or provided a tag or card only attached to the jewellery (with time these have long since vanished).Today there is a substantial secondary market for vintage fashion jewellery and in many instances it has achieved 'collectable' status, increasing in value every year.Most of the vintage costume pieces I feature in my work have been sourced from specialist dealers mainly in the US and UK, many of whom are experts in the field & have consulted on various publications on costume jewellery. Others I find on my travels, however all are selected simply for their beauty & extravagance.
Crystal
Generally glass which contains lead, although the definition can vary from country to country. According to EU rules, glass containing less than 4% lead is defined as 'glass', whereas in the USA it is only 1%. Fully leaded crystal contains at least 24% lead oxide and 'highly leaded' crystal has a minimum of 30%. The presence of lead softens the glass and makes it more accessible for cutting and engraving. It also increases the weight and causes more brilliant light diffraction.
Cubic Zirconia
A cubic form of zirconium oxide (extremely rare in nature) which is created in a laboratory. In the 1970s Soviet scientists perfected the technique for growing the crystals for use primarily in laser technology. In the 1980s Swarovski began mass producing cubic zirconia, it is hard and optically flawless and its use in jewellery became established. A frequently used diamond substitute, it is combined with yttrium oxide and can also be coloured with various other oxides.
Diamond
Transparent crystal of tetrahedrally bonded carbon atoms. The hardest natural material known due to the chemical bonds which form an inflexible three dimensional lattice.
Impurities such as nitrogen, irradiation and plastic deformation (non-reversible change of shape in response to applied force) can colour diamonds as can enhancements such as heating and/or applied irradiation.
The perfect diamond containing no impurities is colourless but in reality most are coloured, with brown and yellow the most common. Pink, orange, green, grey, blue, voilet and red (rarest) are seldom found, sometimes fewer than one in ten thousand. Black 'Carbonado' diamonds contain numerous dark inclusions.
Development and production of synthetic diamonds began in the mid twentieth century, however the growing techniques and processing complications initially rendered them too expensive. New technology has since been developed reducing the cost and allowing for the advancement of commercially viable synthetic diamond production, in particular fancy coloured stones.
Dumorterite
Fibrous crystal often associated with quartz. Commonly greyish blue, denim blue, green-blue but also occurring in violet-reddish purple and brown.
Enamel
A decorative technique in which powdered glass paste is fused onto a metal.
Enhancements/Treatments
Many gemstones are routinely enhanced by various methods in order to improve appearance, durability, appeal, value and availability. This widespread practice includes procedures such as bleaching, dyeing, irradiation, heating, lasering, filling and diffusion - to name a few. Therefore some gemstones used in my creations may have been treated as per the accepted standard in the gemstone industry for that particular variety. I do not use any assembled or imitation gemstones. Any synthetic (manmade) stones will be disclosed in the item description.
Feldspar
A class of aluminium containing silicates which are the most abundant minerals on earth. Feldspathoids resemble Feldspars but have a different structure and much lower silica content.
Fossilisation
The term 'fossil' describes a wide range of natural artifacts. Generally speaking, a fossil is any evidence of past plant or animal life that is preserved in the material of the earth's crust. In most cases, the fossilisation process began when a plant or animal died and was quickly covered with sediments, usually at the bottom of a body of water. The loose sediments protected the bodily remains from the elements, bacteria and other forces that cause weathering and decay. This slowed the decaying process so that some of the remains (in most cases only hard material like bone or shell) were preserved for thousands of years. During this time, sediment layers continued to collect and eventually these sediment layers became hard, solid rock. This process ranges from thousands of years to many millions of years ago. The earliest fossils of complex life date from around 600,000,000 years with recent reports of bacteria revealing up to 3 billion years earlier.
Fluorite
Fine transparent crystal in a range of colours including colourless, yellow, brown, green, blue, violet, pink. Also available in banded varieties of white/blue/violet/purple.
Galalith
Sometimes referred to as French Bakelite, an early plastic made from the natural milk protein, casein. Combined with formaldehyde it was initially developed in 1899, but it took some time to perfect the recipe. It was an easy material to colour and was made to imitate natural materials such as pearls and tortoiseshell and found its niche in buttons, beads, pen barrels and jewellery components. Galalith was also known under several other trade names and found success primarily in Europe. Production ceased mainly in the 1960s with the final British producer stopping manufacture in about 1980.
Garnet
A large family of related silicate minerals, some of which are gemstones. Six common species of garnet are recognised based on their chemical composition. They are pyrope, almandine, spessartite, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. Colours include various shades of red, pinkish red, burgundy, grape, orange, gooseberry, honey yellow/brown, green, black, colourless and the extremely rare blue.
Gaspéite
A rare, bright green, nickel magnesium iron carbonate material named after the place in which it was first discovered, the Gaspé Peninsula, Quebec, Canada in 1966. The best gem quality however, comes from south of Kalgoorlie in Western Australia. It is unearthed during nickel mining and was originally stockpiled for later treatment to remove the nickel ore. For various reasons the stockpiles were abandoned and were sold in 1997 to an American gemstone dealer. Further nickel mining operations have now buried much of this remaining Gaspéite so very little now comes on to the market.
Glass Beads
Vintage glass beads, including crystal, are used in some of my designs. Czechoslovakia, Italy, West Germany and Japan were the prolific and innovative producers each offering different styles. With the onset of World War 2, especially in Europe, the glass industry took a heavy blow as many producers were Jewish. Many factories were shut down as a consequence and were never re-opened. European beads pre-dating the 1940s are highly collectable and have a unique quality and beauty. In the 1960s jewellery fashions went through many changes. Glass beads were expensive and more plastics were being used to cut costs. Several jewellery manufacturers ceased to trade leaving warehouses of unused beads which have been rediscovered and given new life especially in my work. Today's mass produced beads from India and China are considered by many to be inferior.
Gold
Here I have listed the metals added to gold to change its colour (NB: an alloy is a mixture of two or more metallic elements).
- Yellow - alloyed with a mix of 50% copper and 50% silver
- White - alloyed with silver and palladium
- Pink (Rose) - alloyed with a mix of 90% copper and 10% silver
- Green - alloyed with a higher percentage of silver than copper
- Blue - alloyed with a mix that includes indium
- Purple - alloyed with a mix og gold and aluminium
- Grey - alloyed with silver, manganese and copper (popular in jewellery designs from the Art Deco period)
- Black - several methods including: 1, electrodeposition using black rhodium or ruthenium. 2, controlled oxidation containing chromium or cobalt. 3, electroplating solutions containing ruthenium (harder and darker result) of rhodium.
Goldstone
Not actually a gemstone but a type of glass made with copper or copper salts and sometimes cobalt, manganese or chromium. The manufacturing process dates back to the 17th century in Venice and was highly guarded at the time. The most common form of Goldstone is reddish brown containing tiny crystals of metallic copper. Cobalt and manganese substitution results in a product with a more silvery appearance suspended in a strongly coloured matrix known as blue or purple Goldstone. Green Goldstone forms its reflective particles from chromium oxides.
Greenstone (Pounamu)
New Zealand greenstone is a variety of nephrite jade found mainly on the west coast of the South Island. Highly prized by the Maori for weapons, tools and jewellery, export of raw material was made illegal in 1947. Sadly today much of what is sold in New Zealand is in fact Chinese jade.
Hematine
The man made form of haematite (iron oxide). A dark blackish grey with a metallic sheen. Most products on the market today labelled 'haematite' are in fact not natural. The man made variety is considered superior for use in jewellery as it does not rust and is not brittle. Only the man made form can be magnetised and is believed by some to ease joint/arthritic pain. 'Hemalyke' is another trade mark name for this product.
Herkimer Diamonds
Actually not a diamond but a double-terminated quartz found in Herkimer County, New York, and surrounding areas. These quartz crystals grow slowly in vugs (pockets) with very little or no contact with their host rock. They have 18 natural facets, two terminations (points) and can be found clear, cloudy or with a variety of general or rare impurities. Designs featuring wire-wrapping of the crystal are the most prevalent but crystals cut from larger specimens, can be given extra faceting and set into rings etc.
Howlite
A white mineral, calcium borosilicate hydroxide featuring streaks of grey-black. It is frequently dyed and sometimes used to imitate turquoise.
Hypersthene
Magnesium iron silicate, mostly deep brown but also green and grey. Displays a beautiful copper-red schiller.
Igneous Rock
One of the three rock types. It is formed by magma (molten rock) which has cooled and solidified.
Iolite
Sometimes referred to as cordierite or water sapphire, this magnesium aluminium silicate ranges from transparent shades of sapphire blue to blue/violet to yellowish grey to light blue depending on the angle of light as it hits the stone.
Jade
Comprising two distinct minerals, jadeite and nephrite. Occurs in a range of colours including pale to dark green and almost black, white, lilac, grey, blue/green. Jadeite, also known as Chinese jade, is the most valuable.
Jasper
A variety of quartz frequently containing significant amounts of other materials. Commonly dark brownish red, yellow, black, it also features many variegated and banded types. Patterns abound creating many different forms with individual names such as rainforest, ocean, leopard, and network.
Jet
Fossilised wood (type of coal/lignite) from an ancient tree similar to the araucaria or monkey puzzle tree which flourished during the Jurassic period more than 180 million years ago. Whitby, on the Yorkshire coast of England, is the most famous location for top quality jet. It became extremely popular as mourning jewellery during the reign of Queen Victoria after the death of her beloved Prince Albert in 1861. Spanish jet of a lesser grade was also widely used as supplies in Whitby could barely meet the strong demand. Today production of Whitby jet is extremely limited as only that which is washed ashore may be used (mining over the years has led to severe erosion and is now prohibited). Antique pieces fetching increasingly high prices. Please note: French jet is a black glass substitute popular in the late 1800s-1920s.
Karen Silver
Silver produced by the Karen Hillside tribes of Northern Thailand containing 97- 99% pure silver (sterling silver is 92.5% pure). All components are handmade. These communities are members of Fairtrade, and work hard to maintain their culture and craft. The silver is a whiter shade than sterling and does not tarnish easily. I feature beads and clasps in some of my designs. Of particular interest is the range of black silver, actually a lovely shade of gunmetal grey, they produce.
Kyanite
Blue to blue/green silicate mineral with a pearly lustre. It is frequently zoned and with pleochroism near colourless, violet/cobalt blue or different shades of green.
Labradorite
A feldspar with a ground colour of dark smoke grey, but when light strikes in a particular direction, it displays striking rainbow-coloured metallic reflections, or schiller. This is referred to genarally as labradorescence and is mainly caused by the interference of light from lattice distortions, cracks or structural layers breaking up light into special colours. Spectrolite is the vivid coloured variety from Finland and also India.
Lacquer
Lacquer is made from the sap of the Lac tree (Rhus Verniciflua). It has been used for thousands of years both for objects of beauty and for utensils of a practical nature. Many layers are required and each layer must dry for several days before the next can be applied. Cinnabar is a precious pigment which creates the Imperial Red colour used throughtout Asia.
Lapis Lazuli
A rock containing an association of minerals with the main constituent being lazurite (a feldspathoid) in opaque or semi-opaque shades of blue. Patches and veins are common in grey and off-white, as are scattered crystals of gold pyrite.
Larvikite
A greyish blue rock frequently likened to granite. It displays a pearl-grey iridescence, opalescence or even labradorescence on its surface due to the presence of handsom crystals of feldspar. In the past was sometimes used in building construction - notably in Chicago and in the UK.
Lava Stone
Igneous rock (produced from volcanic eruptions). It is usually treated with wax or resing to smooth the abrasive texture. Naturally a greyish black with a porous texture.
Lucite
Lucite is the brand name of a polyacrylic developed by DuPont in 1931. A similar formula called Plexiglass, also known as Perspex was developed around the same time. It combines the properties of both plastic and glass and is approximately 8 times clearer than glass. After World War II Lucite became popular for use in jewellery and today vintage acrylics are in high demand. Lucite and its similar competitors are still being made, but DuPont sold the operations to a UK company in 1993.
Malachite
Distinctive veins and bands of green in various shades identify this mineral. It frequently occurs with blue azurite and is then called azurite-malachite.
Marcasite
A polymorph (different structure) of iron sulphide or white iron pyrite. It has an unstable crystal structure and frequently crumbles. What is used in jewellery and labelled 'marcasite' is actually pyrite. Marcasite jewellery was popular in England as an affordable diamond substitute during the mid-late 18th century (particularly after the death of Prince Albert in 1854) when 'mourning jewellery' was fashionable. Demand continued until the end of the Art Deco period.
Matrix Rock
The host rock in which a mineral specimen is found.
Metamorphic Rock
One of three rock types. It is formed when either igneous, sedimentary or other metamorphic rock is altered by heat, pressure or chemical process.
Mineral vs Rock
Simply put, a mineral is a naturally occurring solid with a definite chemical composition and a specific crystalline structure while a rock is an aggregate of two or more mineral constituents.
Moissanite
Trade name given to silicon carbide and used as a diasmond simulant. History can be traced back to 1893 when Dr Henry Moissan discovered minute mineral quantities of silicon carbide in an ancient meteorite in Diablo Canyon, Arizona. It can be grown in a lab and was used by scientists in the 1960s and 1970s for various applications, but it was not until the 1980s that a proprietory process was developed for producing large single crystals of moissanite. One company has the exclusive manufacturing and marketing rights and in 1998 moissanite jewellery was launched. Moissanite does not grade well on the GIA diamond colour scale, merely an I/J. However, perfect cutting of these stones, very high level of fire and brilliance (exceeding that of diamond) raises the colour perception to white. NB: variation does occur with different cuts, the brilliant is optimal. Poor lighting can affect the brilliance and fire leading to a greenish tinge of the stone. Currently moissanite can be manufactured in clear, green, yellow and blue and is approximately 0ne eighth the price of a diamond.
Moldavite
A type of tektite (solidified splashes of rock melted by the impact of a meteorite than hardening in the air approximately 15 million years ago). It is glass-like and occurs in olive/bottle green transparent-translucent shades. Discovered along the Moldau River Valley in Bohemia and Monrovia, Czechoslavakia. There are now only four active mines and commercial supply may soon be exhausted.
Moonstone
The most common moonstone is of the mineral adularia, a member of the feldspar group. It is characterised by a milky white to bluish shimmering sheen effect across the top of the stone as it is turned and moved (adularescence). Moonstone is also a variety name and not just confined to this one single species. Body colours can range from colourless to grey, brown, yellow, pale orange/peach, green, plum-blue, reddish or pink.
Nautilus
Nautilus is the common name for any marine creature from the cephalopod family nautiidai which has survived for more than 450 million years. It is often referred to as a 'living fossil'. The shell is lined with Mother of Pearl and grows increasingly larger chambers (up to 30) throughout its lifespan of up to 20 years. This noctural creature is found near reefs in the depths of the Indian and Pacific Oceans. But for feeding, mating and laying eggs, it surfaces to shallower water. Taking 5 - 10 years to mature, numbers are decreasing and although some countries have banned sale of their shell, it is not yet listed on CITES (Convention on International Trade for Endangered Species). Whole Nautilus shells were popular display items in the mid-1800 Victorian times, and shells sliced down the centre are used for jewellery.
Niobium
Stable hypo-allergenic metal which can be anodized into various colours.
Obsidian
Volcanic glass formed by rapid cooling of lava. Normally opaque black or grey, it may also be yellow, red, greenish brown and rarely blue. Rainbow obsidian has an iridescent sheen. Mahogany obsidian has brownish/red and black bands. Snowflake obsidian has inclusions of white.
Onyx
A variety of chalcedony similar to agate however the successive bands of colour are parallel. Dyed black for commercial use in jewellery. Sardonyx is the variety with white and black/brown bands.
Opal
A mineraloid gel (mineral-like substance that does not display crystallinity) with a water content usually 3% - 10%, but sometimes as high as 20%. Occurs in the fissures of almost any kind of rock and shades include white, grey, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, black.
- White Opal - opal with a play of colour and light body colour.
- Black Opal - dark background of grey to blue/black displaying the play of colour.
- Boulder Opal - veins of opal in host rock or matrix frequently consisting of chocolate brown ironstone.
- Fire Opal - vibrant red-orange-yellow most notably from Mexico.
- Peruvian Opal - semi-opaque to opaque blue/green, and also pink.
- Water Opal - play of colour appears to be suspended in a colourless transparent body.
- Common Opal - no play of colour, translucent to opaque.
Opalite
Man made opal imitation comprising layered glass or resin with a metal oxide between the layers displaying a milky bluish white translucence.
Palladium
Lustrous silvery white metal belonging to the Platinum group metals.
Pearls
China produces most of the freshwater pearls on the market today and they are the primary type I use in my designs. Cultured and mostly non nucleated, they come in a myriad fanciful shapes and exotic colours. Freshwater pearls today are of superior quality due to changing the type of mussel in the mid 1990s and reducing the number of grafts from 50 down to 24-32. They are harvested between 2 - 6 years, significantly longer than the 6 - 9 months in the 1980s. Rounder and larger nucleated pearls are now also being produced and surface finishes such as faceting are becoming popular. The process of nucleation is easier in freshwater pearls with only mantle tissue being used. This tissue eventually dissolves resulting in solid nacre pearls. Receding can occur up to three times, although subsequent pearls are flatter but colour and lustre may be stronger. Natural colours of freshwater pearls include orange, lavender, pink, cream and enhancements usually involve dyeing and/or irradiation, bleaching or whitening with fluorescent brightening agents and tumble polishing. Mussel hybridisation has also led to the exotic array of colours. (All 'Black' freshwater pearls have been dyed.)
Freshwater pearls are also cultivated in Eastern Central USA, especially the Tennessee River. Shell beads used in saltwater pearl nucleation come from the mussels living in this river. Unlike Chinese and Japanese freshwater pearls, American freshwater pearls are bead nucleated and are grown for up to five years producing a superior and more expensive pearl featuring sticks, crosses and wildly shaped baroques . It is the only type of pearl which is not routinely enhanced.
Saltwater pearls have both a bead and mantle tissue nucleation process and are more susceptible to environmental conditions.
- Akoya Pearls - Saltwater pearls from the Akoya oyster farmed originally in Japan for which Mikimoto is famous. China has now overtaken Japan in production. Also found in Australia, Vietnam and Korea. They are the most consistently round or near-round in the 2-11mm size. Harvesting takes place at around nine to sixteen months with an average of two pearls per oyster being produced. The nacre on these pearls tends not to be as thick as South Sea pearls. They are the most difficult and costly to grow as only 50% survive nucleation, and those that do can produce pearls only once.
- Biwa Pearls - Biwa pearls were originally cultivated in Japan's Lake Biwa, but due to pollution, production largely ceased some time ago. A hybrid pearl mussel crossed between the Biwa pearl mussel and a related species from China is now responsible for what the market commonly refers to as 'Biwas'. These pearls are very smooth and lustrous and command higher prices.
- South Sea Pearls - General term for saltwater pearls found in the area extending from the Philippines, Indonesia down to Australia and across to Tahiti. The largest of all pearls and the most expensive. Harvesting occurs at 2 - 6 years. Australia produces the bulk of the world's White South Sea Pearls while the Golden variety comes mainly from the Philippines, Indonesia and Burma. These pearls may be nucleated up to four times.
- Black Pearls - Famously from Tahiti and the Cook Islands. Natural coloured black pearls are only produced from a few specific types of oyster. Harvesting occurs at 2 - 6 years. Survival rates of these pearls is low, but they may be nucleated up to four times.
- Mabe/Blister Pearls - These terms are used interchangeably to refer to pearls which have grown attached to the inner surface of the shell. The pearl is cut away leaving one side flat, as in the case of a solid blister, or it can have the nucleation bead removed and the resulting hole filled with paste, wax or another bead and then covered with a MOP backing as in the case of an assembled mabe.
- Keshi Pearls - Strictly speaking, keshi pearls form accidentally when the mollusc rejects and spits out the implanted nucleus, or the mantle tissue fractures and forms separate pearl sacs without nuclei. These pearl sacs eventually produce solid nacre pearls. Keshi may be freshwater or saltwater and generally have a high lustre. South Sea and Tahitian Keshi are now rare due to the pearl farms x-raying oysters to determine whether or not the nucleus has been expelled. If it has they are re-nucleated. In today's market many are intentionally cultivated and still referred to as 'Keshi' by dealers.
- Baroque Pearls - Refers to the irregular shape and lack of symmetry. Frequently with 'tails' in varying lengths. One of my personal favourites.
- Coin Pearls - This shape is created by nucleating the mollusc with a flat, disc-shaped implant.
- Mother of Pearl - The smooth, hard, pearly lining of a mollusc.
- Imitation Pearls - Pearl essence (essence d'orient) is the pearly substance given off when fish scales are in water. This substance floats to the surface where it is collected and mixed with varnish. Approximately 2,000 fish are needed to produce one litre of this concentrated product. Many layers of pearl essence are then used to coat a glass or plastic bead. The finest glass pearls are made in the Czech Republic and Swarovski produces the top quality crystal variety. Majorca, from Spain, manufactures a high grade imitation pearl for their own specific range of jewellery. Hollow Glass Beads with the inside surface coated with the pearl essence and then filled with wax are most likely to be found in antique jewellery.
- Shell-based Pearls are either a shell, glass, or plastic bead over which a nail-polish like coating is applied followed by lacquer. Many layers are applied to achieve a fine finish.
- MikimotoMikimoto Kokichi (1858-1954) was a Japanese entrepeneur and is known as the 'Father' of the cultured pearl industry. In 1893 he created hemispherical cultured pearls, 'mabes', but it was not until many years later that he was able to adopt the Mise/Nishikawa technique for the production of spherical pearls. Mise and Nishikawa had each spent time in Australia and had learned the secret to spherical pearl production. In 1916 Mikimoto made arrangements to use this technology and the cultured pearl industry in Japan was born. Expansion was rapid but by 1935 the Japanese pearl industry was facing an over-supply. Plummeting prices encouraged Mikimoto to promote Japanese pearls heavily in the USA and Europe. Publicity stunts such as burning tons of low grade pearls helped establish a reputation that Mikimoto sold only high grade pearls which continues through to this day.
- Hanadama PearlsThese are the finest Japanese Akoya pearls which must pass stringent controls set by the Japanese Pearl Science Laboratory. Only 1-2% of the annual pearl harvest qualifies for Hanadama grade. Lustre, shape (perfectly round), body and nacre (cleanest - min 0.4mm) must all surpass that of AAA Akoyas. Cost is therefore substantially higher and all Hanadama pearls will have an accompanying certificate.
Peridot
Shades ranging from olive to bottle and bright green. It belongs to the mineral group olivine (magnesium iron silicate).
Pewter
Eighy five to ninety per cent tin, with the remainder consisting of copper, bismuth, antimony and in lower grades, lead.
Pietersite
A variety of quartz with fibrous bands of blue, gold and/red tiger's eye. It displays a gentle chatoyancy with the aforementioned colours.
Pleochroism
Optical phenomenon in which gems or crystal appear to be different colours when observed at different angles. Two colours/shades - dichroic, three colours/shades - trichroic.
Polymer
A large molecule composing many repeating structural units connected by chemical bonds. Plastics are a well known polymer and natural polymers include shellac and amber.
Pyrite
Iron sulphide in a metallic yellow colour ranging from pale to brassy. It earned the name 'fools gold' due to its initial similarity to the appearance of gold.
Quartz
One of the most widely distributed minerals in the earth's crust. Occurring in several colours including clear (also known as rock crystal), milky, lemon, rose, smokey, purple (amethyst), yellow (citrine), green (prasiolite or green amethyst). Blue is extremely rare and most on the market is a synthetic product. Quartz with gold needle like inclusions is named rutilated quartz and quartz with black needles of tourmaline is tourmalinated quartz.
Resin
Common name for a class of casting polymers typically requiring two parts. When the parts are mixed they fuse via a chemical reaction resulting in a type of plastic.
Retro Period
1935-1949, here designers struggled with art versus mass production. Natural elements merged with plastics. Many European jewellery firms were shut down due to WWII and several designers emigrated to the USA. The'American' style was glamourous, elegant and sophisticated with a Hollywood flair featuring flowers, bows, ballerinas, sunbursts, moonstones, horse and military motifs. 'Cocktail' rings, often with semi-precious stones such as aquamarine, topaz and synthetics up to 100 carats and the use of rose gold replacing platinum of the Deco era.
Rhinestones
Originally quartz crystals gethered from the Rhine River. This natural source has long since been depleted and Rhinestones are now generally made from glass. On vintage pieces Rhinestones are often referred to as 'paste'. Glass was ground into an actual paste and then moulded and mounted into shape. These manufactured stones had many air bubbles, but these were counteracted by the high lead contect of the glass, faceting, and a backing of metallic paint. The best quality crystal rhinestones are produced mainly in Austria by Swarovski and in the Czech Republic by Preciosa and a few other Bohemian glassworks in Northern Bohemia.
Rhodium
A rare silvery white metal, member of the platinum group and the most expensive precious metal used in jewellery. It is extremely reflective and provides a corrosion and tarnish resistant finish when electro-plated onto other metals.
Rhodonite
A manganese inosilicate occurring in transparent to translucent rose pink to brownish red frequently with black veins running through it.
Roman Glass
Roman Glass is the general term applied to ancient glass made within the vast Roman Empire dating as far back as the 1st century BC. (Glass was invented around 2200 BC in what is now North Western Iran). However, it was not until the 1st Century AD that interest was shown and glass-working became an industry, as opposed to a craft. Ancient Israel was one of the largest glass producers in the Roman Empire and many glass remnants have been unearthed during archaeological digs in the Judean Desert and other Mediterranean countries. Fragments and pieces set into jewellery are broken parts of what were once household items such as vases and drinking vessels, mainly for the wealthy. As manufacturing techniques improved, rapid production enabled its use to become more widespread and available to the general population. Aqua is the common natural colour of untreated glass and after centuries of preservation in the sand, weathered and unusual textures have made every piece unique.
Ruby-Zoisite
Also known as anyolite, a natural combination of ruby and zoisite in a single specimen. Zoisite provides the earthy green and black colour while ruby lends red and pink.
Ruthenium
A member of the Platinum Group Metals, an extremely hard metal used as an alloy for palladium and platinum and also as a surface coating. The colour may be modified from light to dark grey shades.
Sapphire
Variety of corundum occurring in almost every shade except red, whereby the stone is called 'ruby'.
Schiller
Optical phenomenon where a play of colour occurs on the surface of some gemstones. Labradorite, with its flashes of iridescent colour (labradorescence), and moonstone (adularescence) are among the most well known.
Sea Bamboo/Coral
The term 'Coral' refers to a vast array of calcium carbonate secreting marine organisms which grow in varying structures under water. Sea Bamboo is named for its branch-like appearance and is a readily available form of coral used in jewellery. Generally white with black/brown it is then dyed red. Other varieties of coral naturally occurring in red/pink, black, and golden command very high prices while blue has low value due to its porous nature and inability to polish well (blue coral is mostly used for acquariums). Certain species of coral are listed by CITES (Convention on International Trade on Endangered Species) and are prohibited for sale. Coral is porous and can be impregnated with resin to stabilise the product.
Sedimentary Rock
One of the three rock types. It is formed by deposition or consolidation of mineral and organic material and also by precipitation of minerals from solution.
Selenium Glass
Selenium, a metalloid (element with characteristics of both a metal and non-metal) colours glass pink and red shades.
Seraphinite
Mined in Russia, a member of the chlorite group of minerals in shades of forest green to green/black. Inclusions of silvery mica display a chatoyancy or cat's eye effect.
Sodalite
Typically a light to rich royal blue feldspar frequently with veins or patches of white/grey.
Stainless Steel
Generic word for steel with a minimum chromium content of 10.5%. Other elements may also be present, including nickel. Nickel may cause allergies in some people but this is reduced by the use of surgical or hypo-allergenic stainless steel. However a small percentage of nickel remains (the EU has set the limit at 0.05% and the UK 0.01%).
Sugilite
Pure sugilite is a complex silicate which gets its purple colour from manganese. Most of the more variously coloured material ranging from pink-dark purplish black is a rock composed of both sugilite and chalcedony. When chalcedony is present there are also variable amounts of light and dark mottling.
Swarovski
The undisputed leader in crystal bead production. Daniel Swarovski invented the first automatic cutting machine in 1892 and in 1895 the company was established in Wattens, Austria. He went into business at a time when the arts, literature, music and science were cross-pollinating across central Europe. The company was steeped in culture, innovation and creativity from the outset. During the opening decades of the 20th century, Swarovski crystals became an essential ingredient in the world of high fashion. The company worked with iconic figures such as Chanel, Schiaparelli, Balenciaga and later Dior. Swarovski crystal contains approx 32% lead to maximise refraction and many metallic coatings have been formulated, such as the popular AB. In the 1950s and 1960s competition amongst costume jewellery manufacturers was intense. Swarovski was commissioned to produce exclusive combinations for them and in order to keep the designs secret, numbers were assigned to the beads rather than names. Many companies, however, were unable to survive the high production costs associated with their range and the ability to successfully market the jewellery at an affordable price, so eventually had to close and auction off their inventory. Beautiful vintage Swarovski from the 1950s-1970s in sizes or shapes or colours which are no longer produced are available from specialist dealers and are used in some of my work. I also use components currently available and produced by Swarovski.
Synthetic/Imitation Gemstones
Synthetic Gemstones are made in a laboratory and have the same basic chemical composition and similar chemical, optical and physical properties to its natural counterpart. Ruby was the first commercially grown synthetic stone of the early 1900s. Imitation Gemstones merely imitate the colour and look of natural stone and may be made from anything.
Tiger's Eye
Famous for its chatoyancy, this variety of quartz with fibrous inclusions of crocidolite (asbestos) is banded with gold, yellow and brown. The rarer blue counterpart is named hawk's eye and the mahogany is named bull's eye or ox eye.
Tiger Iron
An altered rock, mainly of tiger's eye, red jasper and haematite in bands of undulating colour.
Titanium
High tech super strong and lightweight metal resistant to corrosion. May be anodized into colours.
Topaz
Silicate mineral of aluninium and fluorine. Pure topaz is colourless and transparent but impurities lead to tints in shades such as wine, yellow, grey, reddish-orange, brown and pink (rare). Treatments including heating and/or irradiation can create several other shades and intensities of colour.
Tourmaline
A silicate mineral group with many elements including aluminium, iron, magnesium, sodium, lithium and potassium. Colours abound and include black, green, pink, blue, red and bi-coloured and multi-coloured varieties.
Turitella Fossil
Calcium carbonate with white to grey to pink fossil inclusions.
Turquoise
Hydrated phosphate of copper and aluminium. The various colours result from copper (vivid blue) and iron (softer greens). The presence of matrix rock in black, brown or yellowish-brown create a vein-like appearance. Turquoise is frequently treated, impregnated with wax or resin to improve colour, hardness or to protect against fading. Persian sky blue/robins egg blue is considered superior with Iranian deposits once the most sought after. However the southwestern area of the USA has a number of mines and is now the largest producer in the world of turquoise. Colours include dark green, bright blue, light blue and veined.
Uranium Glass
Up to 2% uranium salts (uranium dioxide) added to glass creating a vivid green glow when under blacklight or sunlight. Ultra violet radiation excites the outer electrons of the uranium atoms which as a result give off energy and is seen by our eyes as this brilliant glow. Originally used in the production of tableware and decorative household items from the mid 19th century, these antiques and retro-era items have become collectible. The beads I use in my work date to around the 1920s-30s and are becoming extremely scarce. Tight regulations on uranium dioxide and the expense of this ingredient have limited the quantities being produced today. I also have a few treasured pieces where manganese was used as the additive and these beads will glow a fainter green under UV light. Please note the radioactivity of the glass is considered negligible and not harmful.
Venetian Glass
Venetian Glass is primarily made on the island of Murano, across the lagoon from Venice. It is world-renowned for being colourful, elaborate and skillfully made. All Venetian Glass production moved to Murano in the 13th Century to protect Venice from the risk of fires, and to keep the glassmaking techniques a secret. The process of making Murano/Venetian Glass is complex and many techniques developed and guarded from centuries ago are still in use today.
Vintage Beads
My personal classification for these artworks of the past are beads manufactured prior to the 1970s with emphasis on the period from the 1920s-1960s. Please refer to specific headings in this glossary.
Zoisite
Calcium aluminium iron sorosilicate mineral. Tanzanite is the most famous in this group but must be artificially heated to bring out the spectacular blue-violet of the stone.
Glossary
© 2010 Kim Ashbridge
Kim Ashbridge
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Kim Ashbridge 2010