different between igneous vs phenocryst

English

From Latin igneus (“fiery”).

igneous (not comparable)

Pertaining to or having the nature of fire; containing fire; resembling fire.
(geology) Resulting from, or produced by, great heat. With rocks, it could also mean formed from lava or magma.

phenocryst (plural phenocrysts)

(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.

Send