Turquoise is a lovely stone that makes exquisite silver turquoise jewelry. Chemically it is a blend of phosphates and aluminum with traces of copper oxide, from which arises its blue color, and manganese oxide, calcium, zinc and iron. The green color of the gems arises from the iron or aluminum and yellow from zinc. The most common color is green for turquoise stones, and furthermore blue gems very often turn green after exposure to sunlight for a long time. Various mixtures of these elements give the gemstone its range of colors, with the most highly prized being those with an intense blue color and yellow colored gemstones having the least value. The finest quality stones, Persian turquoise for instance, do not tend to fade and maintain their attractive blue color for many years.
Some gemstones have a major color and lines of a different color in a spider web pattern on the surface. The cause of this is uneven dispersal of the different elements that are present in the stone and the lines may be brown, yellow or black in many patterns. However unmarked gemstones are more highly prized than gems with a spider web matrix though turquoise stonse of intense blue color, even though they have a spider web matrix, are more highly prized than yellow or green pure colored stones. Natural gems of a pure color, i.e. those which are not marked with spider web matrix, are much rarer and are very highly prized.
Treating Turquoise
About 10% of turquoise used in jewelry is natural, best quality gemstone. More than 90% is treated from soft, rough turquoise to make it hard enough for use in jewelry. This process also increases toughness and develops the gem's color. Turquoise that comes from several countries, for example China, is always too soft and has to be treated. However the process produces beautiful stones, which, although less valuable than unprocessed gems, still make fantastic jewelry. The process enhances the color of the gems and also makes them tougher which makes them last longer. A procedure often used to boost the color consists of injecting a dye in epoxy resin into the gem. The color is more stable and won't change to green. Soft turquoise from China is toughened by injecting the gemstones with a liquid plastic. An alternative approach is to inject epoxy resin alone that will stabilise the gemstone without changing the color.
Simulated turquoise can be made from a base of liquid plastic with powdered turquoise. This sort of turquoise is obviously very cheap. These imitation gems may perhaps be sold as fine quality turquoise turquoise and are often waxed or coated in plastic.
Care of Turquoise Gems
Turquoise is porous and soft so should be carefully looked after. It must never be worn when it can become scratched and must be protected from impact always. Never wear turquoise jewelry when cleaning or digging the garden! Keep turquoise jewelry in a softly lined box and never store with other, harder gemstones which may possibly damage the gems. Turquoise gemstones can soak up liquids so keep them away from oils, chemicals or hot water and even cosmetics and perfumes. These may be absorbed by the gemstone which will change color and lose it's lustre. You can clean turquoise by using mild soapy water and then drying thoroughly with a soft cloth. Make certain it is completely dry before putting it away and on no account use ultrasonic jewelry cleaners as they may cause cracking of the gem.
Conclusion
Turquoise is an exquisite, attractive gemstone which is rare and sought after. Even though there are some disadvantages in that it has to be looked after carefully and some of the blue stones can change to green over time, it makes magnificent silver turquoise jewelry as the attractive blue color is perfectly complemented by the silver.
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