Granite vs. Gneiss: Identifying the Rock in This Specimen #3583277 (License: Personal Use)

The specimen displays prominent banding (foliation) with alternating layers of light-colored feldspar/quartz and dark biotite/hornblende, characteristic of metamorphic gneiss. Its coarse grain size and interlocking texture indicate slow cooling or recrystallization under high-grade metamorphism. Unlike homogeneous granite, the aligned mineral layers suggest directed pressure during formation.

Used in geology education, mineral identification guides, museum exhibits, and online rock databases; targets students, hobbyists, and professionals seeking to distinguish igneous vs. metamorphic textures.