Story: Turquoise Gem; 1-8-2021;
•Turquoise was among the first gems to be mined, and many historic sites have been depleted, though some are still worked to this day.
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium.
It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. Arizona is currently the most important producer of turquoise by value.
In recent times, turquoise, like most other opaque gems, has been devalued by the introduction of treatments, imitations, and synthetics onto the market.
Because the mineral was first brought to Europe from Turkey, from the mines in historical Khorasan Province of Persia. Pliny referred to the mineral as callais, the Iranians named it "pirouzeh" and the Aztecs knew it as chalchihuitl.
Iran has been an important source of turquoise for at least 2,000 years. This deposit is blue naturally and turns green when heated due to dehydration.
The Southwest United States is a significant source of turquoise; Arizona, California (San Bernardino, Imperial, Inyo counties), Colorado (Conejos, El Paso, Lake, Saguache counties), New Mexico (Eddy, Grant, Otero, Santa Fe counties) and Nevada (Clark, Elko, Esmeralda County, Eureka, Lander, Mineral County and Nye counties) are (or were) especially rich.
Sinai, in the Sinai Peninsula, is also among places where the gem is found.
Turquoise prehistoric artifacts (beads) are known since the fifth millennium BCE from sites in the Eastern Rhodopes in Bulgaria. While China has been a minor source of turquoise for 3,000 years or more.
Tt has adorned the rulers of Ancient Egypt, the Aztecs (and possibly other Pre-Columbian Mesoamericans), Persia, Mesopotamia, the Indus Valley, and to some extent in ancient China since at least the Shang Dynasty.
Despite being one of the oldest gems, probably first introduced to Europe (through Turkey) with other Silk Road novelties, turquoise did not become important as an ornamental stone in the West until the 14th century, following a decline in the Roman Catholic Church's influence which allowed the use of turquoise in secular jewellery.
It was apparently unknown in India until the Mughal period, and unknown in Japan until the 18th century.