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Webster 1913 Edition

Noun.

(Chem.)

A compound of antimonious acid and a base or basic radical.

(Min.)

Stibnite.

Noun.

A compound of antimonious acid and a base.

Antimonite

antimonite ‎(countable and uncountable, plural antimonites)

(mineralogy) A grey mineral, antimony sulfide (Sb₂S₃) that is the main source of antimony; stibnite
(countable, inorganic chemistry) Any of several oxyanions of antimony such as H₂SbO₃^-; any salt containing this ion

a grey mineral that is the main source of antimony