pyrocrystalline: Meaning and Definition of

py•ro•crys•tal•line

Pronunciation: (pī"ru-kris'tl-in, -īn", -ēn"), [key]
— adj. Petrog.
  1. crystallized from a molten magma or highly heated solution.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.