How Do Turquoises Form?

What is Turquoise?

Unlike popular transparent gemstones like diamond and aquamarine, gem-quality turquoise doesn’t form as a single solid crystal. Instead, turquoise is a porous mineral aggregate known as a cryptocrystalline rock, comprised of many tiny individual micro-crystals. Chemically, turquoise is a hydrated copper and aluminum phosphate with the formula CuAl₆(PO₄)₄ (OH)₈ · 5H₂O. Depending on the growth environment, its chemical structure may also contain iron, zinc, and other impurities.

Turquoises form via a sedimentary process at the Earth’s surface. Scientists classify turquoise as a secondary mineral since it consists of transformed primary materials cemented into solid stone. In contrast, gemstones like diamond and aquamarine require immense heat and pressure deep in the Earth to crystallize.

Where Do Turquoises Form?

First and foremost a desert gem, turquoise requires a relatively