igneous
Granite
Granite
Hardness: 6-7 on Mohs scale; Color: Mottled grey, white, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained) containing quartz, feldspar, and mica; Specific gravity: 2.63-2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled grey, white, 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 on Mohs scale; Color: Mottled grey, white, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained) containing quartz, feldspar, and mica; Specific gravity: 2.63-2.75.
Formation & geological history
Formed from the slow crystallization of magma below Earth's surface. High silica content suggests origin in continental crust. Occurs in batholiths and mountain ranges worldwide across various geological eras.
Uses & applications
Extensively used in construction for countertops, floor tiles, paving stones, and monuments. Also used as crushed stone for road base and railroad ballast.
Geological facts
Granite is the signature rock of the continental crust. Because it is highly resistant to weathering, it often forms the core of many mountain ranges like the Sierra Nevada and the Himalayas.
Field identification & locations
Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of clear quartz and opaque feldspar. Commonly found in mountainous regions or glacial deposits.
