Vintage Oval Bubble Pendant Charm Bohemian Chain

Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as agem and ornamental stone for thousands of years owing to its unique hue. In recent times, turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the market.The substance has been known by many names, but the word turquoise, which dates to the 17th century, is derived from the French turques for "Turks", because the mineral was first brought to Europe from Turkey, from mines in the historical Khorasan Province of Persia