Granite

Physical Properties

Hardness: 6-7 Mohs; Color: Salt and pepper (white, grey, and black); Luster: Dull to vitreous; Structure: Phaneritic (coarse-grained crystals); Cleavage: None (fractures); Specific Gravity: 2.63 to 2.75

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface. It is a major component of the continental crust and can range from Precambrian to Cenozoic in age.

Uses & Applications

Extensively used in construction for countertops, floor tiles, paving stones, curbing, and monuments due to its durability and aesthetics.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a granite batholith in the Black Hills of South Dakota.

Field Identification & Locations

Identify by its interlocking 'salt and pepper' crystalline texture where individual minerals like quartz, feldspar, and biotite are visible to the naked eye. Found globally in mountainous regions.

Identified on: 5/11/2026

Mode: Standard