subhedral

from The Century Dictionary.

• Having an imperfect crystalline form: said of phenocrysts in a rock which are intermediate between those having a well-developed form (euhedral) and those destitute of this (anhedral).

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective mineralogy Having some crystal faces and some grainy surfaces; neither entirely euhedral nor entirely anhedral.