The name turquoise undoubtedly comes from turc (Turkish in French) as it was transported to Europe through Turkey. 

 

Turquoise, hydrated copper and aluminum phosphate [CuAl₆(PO₄)₄(OH)₈*4H₂O], that is extensively used as a gemstone. Turquoise is a secondary mineral deposited from circulating waters, and it occurs chiefly as an opaque, granular vein running through a host rock. 

 

Turquoise with its blue hue, is among the oldest known gemstones. Turquoise was obtained from the Sinai Peninsula before the 4th millennium BC in one of the world's first important hard-rock mining operations. Turquoise started being used before 4000 BC. 
Turquoise was an important ornamental mineral for jewelry and other object by the ancient Egyptians. It graced the necks of Egyptian Pharaohs and adorned the ceremonial dress of early native Americans. Turquoise has been attributed with healing powers as well as promoting the wearer's status and wealth. A very special stone indeed, Turquoise is a sacred stone to many American Indian tribes and has been used in various jewelry items.

 

Turquoise has been thought to warn the wearer of danger or illness by changing color. In the 13th century,turquoise was thought to protect the wearer from falling, especially from horses. 
Turquoise is also believed to bring happiness and good fortune to all. It's said that turquoise attracts healing spirits, making it a premier healing stone.
Believed to be a protective stone, turquoise is worn to guard against violence and accidents. Turquoise is also a valuable amulet for travelers.