Coarse-grained Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Mottled cream, tan, and dark brown/black; Luster: Dull to vitreous (quartz grains); Crystal structure: Phaneritic (visible crystals); Cleavage: Perfect on feldspar grains; Specific gravity: 2.63 to 2.75

Formation & Geological History

Formed by the slow cooling and crystallization of silica-rich magma deep underground. This slow cooling allows for the large, visible mineral grains. Typically found in batholiths and continental shields.

Uses & Applications

Widely used in construction (countertops, tiles, paving), monuments, and as crushed stone for aggregate.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. It is extremely durable and resistant to weathering compared to other rock types.

Field Identification & Locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals. It is found in mountain ranges and areas where deep crust has been uplifted and eroded.

Identified on: 5/19/2026

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