Granite

Physical Properties

Hardness: 6-7 Mohs; Color: Speckled cream, tan, grey, and black; Luster: Vitreous to dull; Crystal structure: Coarse-grained (phaneritic); Cleavage: Indistinct; Specific Gravity: 2.63 - 2.75

Formation & Geological History

Formed from the slow crystallization of magma below the Earth's surface (intrusive). Most granites are Precambrian to Cenozoic in age and form in continental crust near subduction zones or within mountain-building belts.

Uses & Applications

A primary material in construction for countertops, floor tiles, and paving stones. Also used for monuments, sculptures, and as crushed stone for road aggregate.

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 is unique to Earth among the planets in our solar system.

Field Identification & Locations

Identify by its 'salt and pepper' look where individual mineral grains (Quartz, Feldspar, Mica) are clearly visible to the naked eye. Commonly found in large batholiths or mountain ranges. For collectors, look for uniform grain size and lack of layering.

Identified on: 4/17/2026

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