phenocryst

English

Etymology

pheno- +‎ -cryst

Noun

phenocryst (plural phenocrysts)

1. (mineralogy) Any relatively large crystal embedded in a more fine-grained or glassy igneous rock
   • 1965, Gordon A Macdonald and Takashi Katsura, Eruption of Lassen Peak, Cascade Range, California, in 1915: Example of Mixed Magmas, Geological Society of America Bulletin 76 (5), pages 475:

     Some of the feldspar phenocrysts are more than 1 cm long, but most are less than 5 mm.

Synonyms

• phenocrystal

Derived terms

• phenocrystic

Translations

Any relatively large crystal embedded in a more fine-grained or glassy igneous rock

• Finnish: hajarae