The word “turquoise” is an old French adjective, used to describe objects taken from the region of Turkey. One of these objects includes beautiful sky blue to green stones, which were originally mined in the Sinai Peninsula or over 5,000 years, thereby making turquoise one of the first gemstones to be mined.
Today, turquoise is most commonly found in the southwestern United States, Mexico, China, Chile, Egypt, and Iran.
Turquoise is a hydrated copper aluminum phosphate mineral. Its chemical composition is CuAl6(PO4)4(OH08)-4H20. Its composition can be variable, and even turquoise deposits in the same general area can have slightly different chemical compositions.
It is a secondary mineral that forms in arid or semi-arid regions, when rainfall leaches copper, aluminum, and phosphorus out of host rocks (plutonic and volcanic igneous rocks, or sedimentary phosphate beds). The leached material can also include impurities (strontium, lead, etc.). When the requisite elements are in the right combination, they get re-precipitated as nodules, encrustations, in veins, or in massive form.
Two views of a nugget (5 cm width) of turquoise with “spiderweb” cracks:
Lastly, a view of a thin crust (2.5 cm length) of turquoise:
At certain locales in the southwestern United States, turquoise can be found as the result of weathering of hydrothermal porphyry-copper deposits (PCDs). For more information about PCDs, see my previous Post.
Also, in the southwestern United States, turquoise typically forms within 100 feet of the ground surface. The shallow depth allowed Indigeous Americans to mine mineral in areas now known as Arizona and New Mexico.
Your blog post has ignited my curiosity about gemstones and their historical significance. It's incredible how gemstones can have such profound effects on our emotions. I will recommend you The 10 Best Crystals for Self-Love and Confidence
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