Turquoise (color)

Turquoise /ˈtɜːrkɔɪz/ or /ˈtɜːrkwɔɪz/ is the name of a greenish blue color, based on the gem of the same name. The word turquoise comes from the French for Turkish, as the gem was originally imported from Turkey. The first recorded use of turquoise as a color name in English was in 1573. It is, generally thought to consist of 70% blue and 30% green.

The X11 color named turquoise is displayed on the right.

Turquoise gemstones

Turquoise is an opaque, blue-to-green mineral that is a hydrous 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 a gem and ornamental stone for thousands of years owing to its unique hue.

In many cultures of the Old and New Worlds, this gemstone has been esteemed for thousands of years as a holy stone, a bringer of good fortune or a talisman. The oldest evidence for this claim was found in ancient Egypt, where grave furnishings with turquoise inlay were discovered, dating from approximately 3000 BC. In the ancient Persian Empire, the sky-blue gemstones were earlier worn round the neck or wrist as protection against unnatural death. If they changed color, the wearer was thought to have reason to fear the approach of doom. Meanwhile, it has been discovered that turquoise can change color. The change can be caused by light, or by a chemical reaction brought about by cosmetics, dust or the acidity of the skin.