microphenocryst

English

Etymology

From micro- +‎ phenocryst.

Noun

microphenocryst (plural microphenocrysts)

1. (geology) A very small crystal in a fine-grained porphyritic rock.
   • 1983, U.S. Geological Survey Bulletin, page 9:

     The basalt of Goose Island of the Ice Harbor Member is unique for the occurrence of microphenocrysts of ilmenite and titanmagnetite.