Granite

Physical Properties

Hardness: 6-7 Mohs; Color: Salt and pepper (white, gray, black); Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained); Specific Gravity: 2.63-2.75

Formation & Geological History

Formed from the slow cooling and crystallization of magma deep beneath the Earth's surface (plutonic). Found in continental crust plates across all geological ages.

Uses & Applications

Extensively used in construction for countertops, floor tiles, paving stone, monuments, and as crushed stone for road base.

Geological Facts

Granite makes up a large part of the continental crust. It is one of the hardest natural stones and Mount Rushmore is carved into a granite batholith.

Field Identification & Locations

Identify by its interlocking 'salt and pepper' crystalline texture where minerals like quartz, feldspar, and mica are large enough to see with the naked eye.

Identified on: 5/2/2026

Mode: Standard