Porphyroblastic Texture

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Porphyroblastic Texture

 

the uneven granular texture of a rock caused by the presence of large crystals, or porphyroblasts, in a fine-grained groundmass. Unlike phenocrysts, porphyroblasts form during recrystallization in the course of metasomatism of solid rock. Porphyroblasts include garnet, kyanite, staurolite, andalusite, microcline, albite, mica, tourmaline, topaz (in greisens), and aegirine (in fenites).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The porphyroblastic texture is described by garnet and some plagioclase (Figure 3e).
The presence of both porphyroblastic textures and anhydrite relics clearly points to anhydrite as the gypsum's precursor.