igneous
Granite
Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)
Hardness: 6-7 Mohs; Color: Pinkish-tan with grey and black minerals; Luster: Vitreous to dull; Crystal Structure: Phaneritic (coarse-grained); Cleavage: Perfect in feldspars, none in quartz.
- Hardness
- 6-7 Mohs
- Color
- Pinkish-tan with grey and black minerals
- Luster
- Vitreous to dull
Identified More igneous →
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Physical properties
Hardness: 6-7 Mohs; Color: Pinkish-tan with grey and black minerals; Luster: Vitreous to dull; Crystal Structure: Phaneritic (coarse-grained); Cleavage: Perfect in feldspars, none in quartz.
Formation & geological history
Formed through the slow crystallization of magma below the Earth's surface (intrusive). Common in continental crust and mountain ranges, often dating back hundreds of millions to billions of years.
Uses & applications
Extensively used as a dimension stone in construction, countertops, monuments, and as crushed stone for road base and aggregate.
Geological facts
Granite makes up the majority of the Earth's continental crust. Mount Rushmore is carved into a massive granite batholith in the Black Hills of South Dakota.
Field identification & locations
Identified in the field by its visible interlocking crystals of quartz and pink/orange feldspar. It is found in mountain cores and shield areas worldwide.
