Granite

Physical Properties

Hardness: 6-7 Mohs; Color: Salt and pepper/greyish-tan; Luster: Dull to vitreous; Structure: Phaneritic (coarse-grained) crystalline; Cleavage: None (fractures), though feldspar crystals within may exhibit cleavage.

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface (intrusive). Usually associated with mountain-building events in the continental crust. Can date back billions of years depending on location.

Uses & Applications

Used extensively 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. It is extremely durable and resistant to weathering, which is why it is used for prominent landmarks like Mount Rushmore.

Field Identification & Locations

Identify by its 'salt and pepper' appearance and visible interlocking crystals of different colors (clear/white quartz, pinkish/tan feldspar, dark mica). Common in mountain ranges and batholiths worldwide.

Identified on: 4/17/2026

Mode: Standard