igneous
Granite Cobble
Granite
Hardness: 6-7 (Mohs scale); Color: Salt-and-pepper (white, gray, black); Luster: Dull to vitreous; Structure: Phaneritic (coarse-grained); Composition: Quartz, Feldspar, and Mica.
- Hardness
- 6-7 (Mohs scale)
- Color
- Salt-and-pepper (white, gray, black)
- Luster
- Dull to vitreous
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Physical properties
Hardness: 6-7 (Mohs scale); Color: Salt-and-pepper (white, gray, black); Luster: Dull to vitreous; Structure: Phaneritic (coarse-grained); Composition: Quartz, Feldspar, and Mica.
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground. This specific specimen has been rounded by water transport or glacial action. Formation can range from hundreds of millions to billions of years ago.
Uses & applications
Building material, countertops, architectural stone, road base, and decorative landscaping rock.
Geological facts
Granite makes up a large portion of the Earth's continental crust. It is extremely durable and resistant to weathering compared to other rock types.
Field identification & locations
Identify by its interlocking crystalline texture and visible grains of clear quartz, white/pink feldspar, and dark biotite or hornblende. Commonly found in riverbeds, glacial deposits, and mountain ranges.
