igneous
Granite
Granite (Felsic Plutonic Rock)
Hardness: 6–7 on Mohs scale; Color: Mottled grey, white, and black; Luster: Phaneritic (crystalline) and vitreous; Crystal structure: Coarse-grained granular; Specific gravity: Approx 2.63 to 2.75.
- Hardness
- 6–7 on Mohs scale
- Color
- Mottled grey, white, and black
- Luster
- Phaneritic (crystalline) and vitreous
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Physical properties
Hardness: 6–7 on Mohs scale; Color: Mottled grey, white, and black; Luster: Phaneritic (crystalline) and vitreous; Crystal structure: Coarse-grained granular; Specific gravity: Approx 2.63 to 2.75.
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground (intrusive). They are primarily found in continental crust and can range in age from the Archean Eon to the Cenozoic Era.
Uses & applications
Extensively used in construction as dimension stone, countertops, floor tiles, and as crushed stone for road base and concrete aggregate.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Famous peaks like Yosemite's Half Dome and Mount Everest's upper sections are composed of granite.
Field identification & locations
Identify by its 'salt and pepper' appearance and visible interlocking crystals of quartz, feldspar, and mica. Commonly found in mountain ranges and Shields (like the Canadian Shield). It will not be scratched by a steel knife.
