Granite

Physical Properties

Hardness: 6-7 on Mohs scale. Color: White, buff, or pink with dark specks. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained). Specific gravity: 2.63-2.75.

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface. Primarily found in continental crust and mountain ranges, often dating back hundreds of millions to billions of years.

Uses & Applications

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

Geological Facts

Granite is one of the hardest substances in the world, second only to diamonds. It makes up a large portion of the Earth's continental crust and involves minerals like quartz and feldspar.

Field Identification & Locations

Identify in the field by its interlocking 'salt and pepper' appearance of crystals. Common in mountain belts and shield areas. Collectors look for large crystals of constituent minerals like muscovite or feldspar.

Identified on: 4/30/2026

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