Turquoise is a particularly problematic stone when it comes to verifying its authenticity. It consists of a phosphate of aluminium, colored by copper and traces of iron. Some gemologists believe that the beautiful blue color is produced by a complex ion formed from copper and ammonium. The finest colored material is mined and worked in Iran, its colors range from the highly desirable sky blue to a bluish green. Besides, The color of turquoise is sometimes affected by the acid perspiration of certain wearers. When this happens, the stone will become green or greenish, as it also does if it becomes too warm. The color is also affected by the alcohol content in perfume, hair sprays and cosmetics. Ranging from blue-green, to yellow-green with grey, black or brown veining .
The stones were first exported to Germany, where they became known as Turkisher Steins, which translates as “Turkish stones”. When the stones reached France, the German name became translated into Pierre turquoise - stone of Turkey. That’s why turquoise jewelry got its name from the Turkish merchants who first carried this beautiful and very desirable blue stone to Europe for trade.
Trudging the commercial trade routes from the East, they drove great camel caravans burdened with sacks of exotic, aromatic spices, bolts of cloth encrusted with gemstones and interwoven with gold and silver threads, and all kinds of pearl jewelry and other treasures.
Turquoise is porous, so contact with liquids, oils or even perspiration should be avoided. Jewelry should be removed before washing. Turquoise is commonly impregnated with plastic, colorless oil or wax to improve color and increase durability. Untreated turquoise will eventually turn green. As genuine Chinese green turquoise jewelry is expensive, reconstituted turquoise is made today. Crafted from real turquoise chips fused with other stones to cut the cost. Turquoise is the birthstone for the month of December.
As to Chinese Turquoise, much Chinese turquoise was used for artistic carving and turquoise jewelry, which has always been popular in the Orient. In China, Turquoise dates to the thirteenth century A.D. Although most brought from trade with the Persians, Turks, Tibetans, and the Mongols. Tibet had it’s own source of turquoise usually a green cast, very hard stone with significant amount of spider webbing. The Tibetans highly revered turquoise and was used in many areas as currency.
Turquoise is believed to protect the wearer from danger. In various countries, it is believed to fade when illness or danger is near. Another belief is that a fading stone indicates a lover’s faithlessness or a friend’s disaffection.