Granite

Physical Properties

Hardness: 6-7 (Mohs scale); Color: White, pink, grey with black specks; Luster: Vitreous to pearly; Crystal structure: Phaneritic (coarse-grained); Cleavage: Indistinct; Specific Gravity: 2.63-2.75

Formation & Geological History

Formed through the slow crystallization of magma below Earth's surface. It is a plutonic rock that cools over millions of years, allowing large crystals to form.

Uses & Applications

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

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' appearance and visible crystals. Found globally in mountainous regions and continental shields like the Canadian Shield.

Identified on: 5/6/2026

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