- Textural term for
igneous rocks in which large
crystals, called phenocrysts, are set in finer
groundmass, which may be crystalline or
glass or both.
Source: Leet, L. Don. 1982.
Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall
- a. Said of the texture of an igneous rock in which larger crystals
(phenocrysts) are set in a finer-grained groundmass, which may be
crystalline or glassy or both. Also, said of a rock with such texture, or
of the mineral forming the phenocrysts. AGI
b. Pertaining to or resembling porphyry. AGI
Dictionary of Mining, Mineral, and Related Terms