Stone Science

Textures & fabrics

Scientific words for what you can see: grain size, sorting, alignment, and crystal relationships.

Weathered rock surface showing mineral vein and texture
Vocabulary

Common texture terms

Texture/fabric terms are used across all rock types, but they mean slightly different things in each context.

Grain size

Aphanitic (fine), phaneritic (coarse), pegmatitic (very coarse), glassy (no crystals).


Crystal relationships

Equigranular, porphyritic (phenocrysts + groundmass), interlocking, poikilitic.


Sedimentary textures

Sorting, rounding, matrix vs. cement, clast-supported vs. matrix-supported.


Metamorphic fabrics

Foliation, schistosity, gneissic banding, lineation, granoblastic texture.

Texture examples

A visual set of textures and fabrics referenced in scientific descriptions.

Back to Stone Science

Return to the overview page to continue into geochemistry and rock-forming minerals.