Turquoise is one of the oldest known gems..

The name “Turquoise” may have come from the word Turquie, French for Turkey, because of the early belief that the mineral came from that country (the turquoise most likely came from the Alimersai Mountains in Persia (now Iran) or the Sinai Peninsula in Egypt, two of the world's oldest known turquoise mining areas.)

Another possibility could be the name came from the French description of the gemstone, "pierre turquin" meaning dark blue stone.