Word Study
biotite
CIDE DICTIONARY
biotite, n. [From Biot, a French naturalist.].
Mica containing iron and magnesia, generally of a black or dark green color; -- a common constituent of crystalline rocks. See Mica. [1913 Webster]
OXFORD DICTIONARY
biotite, n. Mineral. a black, dark brown, or green micaceous mineral occurring as a constituent of metamorphic and igneous rocks.
Etymology
J. B. Biot, Fr. physicist d. 1862
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