Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Pinkish-tan with some dark speckles; Luster: Vitreous to dull; Crystal structure: Phaneritic (large, coarse-grained crystals); Cleavage: Indistinct; Specific Gravity: 2.63 to 2.75.

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface (intrusive). Most granites are associated with continental crust and can range from Precambrian to Cenozoic ages.

Uses & Applications

Used extensively in construction for countertops, floor tiles, paving stones, and memorial monuments. Also used as crushed stone for road bases.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. Because of its durability and hardness, it has been used in architecture since Ancient Egypt (e.g., the Red Pyramid).

Field Identification & Locations

Identify in the field by its speckled, interlocking crystalline texture where individual grains of pink feldspar and clear quartz are visible. Common in mountainous regions with exposed batholiths.

Identified on: 4/21/2026

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