turquoise

A blue to blue-green mineral of aluminum and copper, mainly CuAl6(PO4)4(OH)8·4H2O, prized as a gemstone in its polished blue form.

A light to brilliant bluish green.

An opaque blue or greenish-blue precious stone, consisting essentially of a phosphate of aluminium containing a little copper and iron.

Having a fine light blue color, like that of choice mineral turquoise.

A hydrous phosphate of alumina containing a little copper; calaite. It has a blue, or bluish green, color, and usually occurs in reniform masses with a botryoidal surface.