Turquoise from the U.S.A. set in India silver (gold overlay) in free form (delivered assorted)

The mineral turquoise is a hydrated copper-aluminum phosphate with the chemical formula CuAl6(PO4)4(OH)8·4(H2O). The green, yellow-gray, light blue, but typically blue-green turquoise has a waxy sheen and a pale blue-white stripe color. The crystal system is triclinic and the cleavage is perfect according to the crystal plane [001] and good according to [010]; However, it almost only occurs in cryptocrystalline forms, so the fission cannot be observed in practice. The average density is 2.7 and the hardness is 5 to 6. Turquoise is not radioactive. The mineral turquoise is named after Turkey, the country it passed through when the mineral first reached Europe; As far as we know, it does not occur in Turkey. The color turquoise is named after this mineral. Turquoise is mainly found as a secondary mineral in copper ores. The type location is the Nishapur deposit in Iran. The mineral was also mined in Sinai and in Serabit el-Khadim there is a temple dedicated to the Egyptian "Lady of Torquoise", (the goddess Hathor). Turquoise is used as a semi-precious stone. During the Ottoman Empire, turquoise was exported as a precious mineral, especially to Persia. Turquoise is currently mined in Mexico, the United States, China and Iran. Imitation turquoise was first created in France in 1972, but the properties of this imitation differ from those of the natural varieties. Yet the best-selling turquoise is now synthetic.