igneous
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)
Hardness: 6-7 Mohs; Color: Salt and pepper (white, grey, and black); Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained, visible crystals); Specific gravity: 2.63 - 2.75.
- Hardness
- 6-7 Mohs
- Color
- Salt and pepper (white, grey, and black)
- Luster
- Dull to vitreous
Identified More igneous →
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Physical properties
Hardness: 6-7 Mohs; Color: Salt and pepper (white, grey, and black); Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained, visible crystals); Specific gravity: 2.63 - 2.75.
Formation & geological history
Formed from the slow crystallization of magma below Earth's surface. It is a plutonic igneous rock that develops over millions of years within the continental crust.
Uses & applications
Widely used in construction 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. Because it is very hard and resistant to erosion, it often forms the core of many mountain ranges.
Field identification & locations
Check for a 'salt and pepper' appearance with interlocking crystals of translucent quartz, opaque white or pink feldspar, and black biotite or hornblende. Commonly found in batholiths and mountain outcrops.
