igneous
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
Hardness: 6-7 on Mohs scale. Color: Mottled gray, white, and translucent. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained visible crystals). Cleavage: Varies by mineral (feldspar has 2 directions). Specific gravity: 2.63 to 2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled gray, white, and translucent
- Luster
- Vitreous to dull
Identified More igneous →
Explore Granite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale. Color: Mottled gray, white, and translucent. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained visible crystals). Cleavage: Varies by mineral (feldspar has 2 directions). Specific gravity: 2.63 to 2.75.
Formation & geological history
Formed from the slow subterranean cooling and crystallization of magma. Usually associated with continental crust and formed over millions of years through intrusive volcanic processes.
Uses & applications
Used extensively in construction for countertops, floor tiles, paving stone, curbing, and monuments. Also used as crushed stone for road base and concrete aggregate.
Geological facts
Granite makes up a large portion of the Earth's continental crust. Its name comes from the Latin word 'granum,' meaning a grain, in reference to its coarse-grained structure.
Field identification & locations
Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of quartz, feldspar, and mica. It is extremely hard and cannot be scratched by a steel knife.
