Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Pink, gray, white, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: Indistinct; Specific Gravity: 2.63-2.75

Formation & Geological History

Formed by the slow crystallization of magma below Earth's surface. It is a plutonic rock that makes up much of the continental crust, often appearing in mountains and cratons.

Uses & Applications

Extensively used in construction for countertops, floor tiles, paving stone, curbing, and monuments. Also high value as an ornamental stone in architecture.

Geological Facts

Granite is one of the hardest substances in the world, second only to diamonds. It is also an intrusive rock, meaning it cooled underground over thousands of years to form large crystals.

Field Identification & Locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of quartz and feldspar. Found worldwide in mountainous regions and shield areas.

Identified on: 5/2/2026

Mode: Standard