igneous
Granite
Phaneritic Granocrystalline Igneous Rock
Hardness: 6-7 Mohs; Color: Mottled brown, tan, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Composition: Quartz, Feldspar, and Biotite Mica.
- Hardness
- 6-7 Mohs
- Color
- Mottled brown, tan, and black
- Luster
- Vitreous to dull
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Mottled brown, tan, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Composition: Quartz, Feldspar, and Biotite Mica.
Formation & geological history
Formed from the slow crystallization of silica-rich magma below the Earth's surface (intrusive). Most granite formations date from the Precambrian to Cenozoic eras.
Uses & applications
Widely used in construction for countertops, floor tiles, paving stones, curbing, monuments, and as an aggregate in road building.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a granite batholith, and the rock is famous for its extreme durability and resistance to weathering.
Field identification & locations
Identifiable by its 'salt and pepper' or multicrystalline appearance where individual minerals are visible to the naked eye. Commonly found in mountainous regions or shield areas like the Canadian Shield.
