igneous
Granite
Granite (Felsic Plutonic Rock)
Hardness: 6-7 Mohs; Color: Salt and pepper (white/pink feldspar, gray quartz, black mica); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained coarse crystals); Cleavage: Individual minerals vary (feldspar has 2 planes at 90 degrees); Specific Gravity: 2.63 - 2.75
- Hardness
- 6-7 Mohs
- Luster
- Vitreous to dull
Identified More igneous →
Explore Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Salt and pepper (white/pink feldspar, gray quartz, black mica); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained coarse crystals); Cleavage: Individual minerals vary (feldspar has 2 planes at 90 degrees); Specific Gravity: 2.63 - 2.75
Formation & geological history
Formed through the slow crystallization of magma below Earth's surface (intrusive). Most continental granite dates from the Precambrian to Cenozoic eras, typically forming in continental crust above subduction zones or in mountain-building regions.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stones, curbing, monuments, and as aggregate for road base and concrete.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a granite batholith. It is one of the hardest and most durable materials used in human architecture.
Field identification & locations
Identify in the field by its coarse-grained interlocking crystals and lack of foliation. Common in mountain ranges and Shields (like the Canadian Shield). Look for visible specks of quartz (translucent gray) and feldspar (opaque white/pink).
