CHAPTER XIII
TURQUOISE
T
URQUOISE is a
popular gem mineral today, as it was anciently with the Persians and
the Aztecs, whose name for it was chalchi-huitl. Turquoise is a French
word, meaning a Turkish stone, also the feminine of Turkish. Turquoise
is an amorphous stone occurring in kidney-shaped nodules and
incrustations; its colour is various shades of azure or robin's egg
blue. Of Persian origin, it is supposed to be the stone anciently
referred to, in Pliny's natural history, as callais, callaina, and
callaica. In his catalogue of gems in the United States National
Museum, Wirt Tassin applies to turquoise the names callainite and
turkis; Cat-telle says it is known to scientists as " callaite ";
Oliver Cummings Farrington in his Gems and Gem Minerals describes callainite as a distinct mineral.
The hardness of turquoise is 6; specific gravity, 2.6 to 2.8; there is no cleavage; it is brittle
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