igneous
Granite
Granite (composed mainly of Quartz, Alkali Feldspar, and Plagioclase)
Hardness: 6-7 Mohs; Color: Pink, red, white, or gray with dark specks; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained crystals); Cleavage: Interlocking crystals (no distinct cleavage of the rock itself); Specific Gravity: 2.63 - 2.75
- Hardness
- 6-7 Mohs
- Color
- Pink, red, white, or gray with dark specks
- 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: Pink, red, white, or gray with dark specks; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained crystals); Cleavage: Interlocking crystals (no distinct cleavage of the rock itself); Specific Gravity: 2.63 - 2.75
Formation & geological history
Formed by the slow crystallization of magma below Earth's surface (intrusive). It is found in large plutons or batholiths, often dating back hundreds of millions to billions of years.
Uses & applications
Widely used as a construction material for countertops, floor tiles, paving stones, curbing, monuments, and as crushed stone for road base.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a massive granite outcrop in South Dakota.
Field identification & locations
Identify by its salt-and-pepper appearance and visible crystals of quartz (clear/gray) and feldspar (pink/white/tan). Common in mountain ranges and glacial deposits.
