from
The Collaborative International Dictionary of English v.0.48
Turquoise \Tur*quoise"\, Turquois \Tur*quois"\ (?; 277), n. [F.
turquoise; cf. Pr. & Sp. turquesa, It. turchese, turchina,
LL. turchesius, turchina; -- so called because first brought
from Turkey. See 1st {Turkey}.] (Min.)
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.
[Formerly written also {turcois}, and {turkois}.]
[1913 Webster]
Note: Turquoise is susceptible of a high polish, and when of
a bright blue color is much esteemed as a gem. The
finest specimens come from Persia. It is also found in
New Mexico and Arizona, and is regarded as identical
with the chalchihuitl of the Mexicans.
[1913 Webster]