idiomorphic
adjective
Also (in a rock) noting or pertaining to a mineral constituent having its own characteristic outward crystalline form unaltered by the other constituents of the rock; automorphic.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The ferromagnesian minerals crystallize comparatively early and have some idiomorphism; the felspar usually follows and only in part shows good crystalline outlines.
From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 5 "Dinard" to "Dodsworth" by Various