Turquoise is a mineral species formed hydrous phosphate of copper and aluminum, whose chemical composition is CuAl6 (PO4) 4 (OH) 8.4 H2O.
Its name comes from "Turkish stone" because it was especially known in Europe at the time of the Crusades. She gave her name to the color turquoise, a shade of blue. Iranians call "Firouze". The Turks used the same name, the ore from Iran. Europe having received turkey call "turquoise".
Blue colored stone, not transparent (Semi-opaque), sometimes translucent on the edges. Variety of alumina phosphate, called old school, especially highly sought azure. Easily recognizable with its sky-blue color, sometimes greenish. Infusible torch, dissolves in acids without effervescence, without residue, offering coloring copper. Sometimes bright turquoise blue to spend dull blue: it is said they are dead or extinct.
Operation Turquoise is very old; though many deposits are now exhausted, yet others provide some stones. The main deposits are located in Mexico and the United States. It is located around the Red Sea. Those trade come from Iran and Turkey. Turquoise is found in masses, always amorphous, sometimes forming small veins involved in their matrix or small kidneys.
Since at least 2000 years, Iran remains one of the most important producing regions of the world. One of the oldest deposits is that of Mount Ali Mersai in the province of Khorasan.
Under the first dynasty of pharaohs, and perhaps before, the Egyptians used turquoise and extracted from the Sinai Peninsula. Mines Serabit el-Khadem and Wadi Maghareh may represent the oldest mines. Their color is greener than Iranian stones.
Previously found a lot of turquoise in the states of South-western United States (Arizona, California, Colorado, New Mexico, Nevada). Today, only the site of Apache Canyon California gives good yields.
Mine Montebras-en-Soumans near Boussac, Creuse, Limousin, France is the only deposit turquoise Europe…
Long time, it is appreciated and used by artisans and goldsmiths as a gemstone. Today, it competes with imitations and synthetic substitutes. Be careful not to confuse it with the variscite for its green variant in areas of Utah and Nevada.
Turquoise and argillite anasazi, found in Chaco Canyon, eleventh or twelfth century
Howlite colored to imitate turquoise blue (Turquenite)
Set of woman Ladakh.