The Collaborative International Dictionary
Idiomorphous
Idiomorphous \Id`i*o*morph"ous\, a. [Gr. 'idio`morfos of peculiar form; 'i`dios peculiar + morfh` form.]
Having a form of its own.
(Crystallog.) Apperaing in distinct crystals; -- said of the mineral constituents of a rock.
Wiktionary
idiomorphous
a. 1 having a unique, characteristic form 2 (context mineralogy English) occurring as distinct crystals