Turquoise

Turquoise is an opaque, hydrated, blue-to-green copper aluminium phosphate mineral. It is rare and valuable in finer grades and has been enjoyed as a gem and ornamental stone for thousands of years owing to its unique hue. In recent times turquoise—like most other opaque gems—has had its popularity undermined by the introduction of treatments, imitations, and synthetics onto the market, some difficult to detect even by experts. The word "turquoise" is very old and of uncertain origin, derived from the French pierre turquoise, meaning "Turkish stone." This is thought to have arisen from a misconception: turquoise does not occur in Turkey but was traded there, and the gem became associated with the country in the West.