igneous
Granite / Gneiss (Coarse-Grained Felsic Rock)
Granite (Quartz-Feldspar-Mica aggregate)
Hardness: 6-7 on Mohs scale. Color: Speckled grayish-tan with reflective golden/silvery flecks (muscovite/biotite mica). Luster: Vitreous to pearly on mica flakes. Texture: Coarse-grained (phaneritic).
- Hardness
- 6-7 on Mohs scale
- Luster
- Vitreous to pearly on mica flakes
Identified More igneous →
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Speckled grayish-tan with reflective golden/silvery flecks (muscovite/biotite mica). Luster: Vitreous to pearly on mica flakes. Texture: Coarse-grained (phaneritic).
Formation & geological history
Formed by the slow cooling and crystallization of felsic magma deep beneath the Earth's surface (plutonic environment) or modified through regional metamorphism.
Uses & applications
Used as dimension stone, building material, decorative aggregate, gravel, and countertop material.
Geological facts
Granite makes up a large portion of Earth's continental crust. The glittering flecks in this specimen are mica minerals, which reflect light brightly along cleavage planes.
Field identification & locations
Identified by its speckled appearance containing quartz, feldspar, and shiny mica plates. Found worldwide in mountain ranges, batholiths, and glacial till. Common field specimen.
