Granite

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Pinkish-tan, white, and grey; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: Dependent on mineral (feldspar has 2 directions); Specific gravity: 2.63 to 2.75

Formation & Geological History

Formed through the slow crystallization of magma below the Earth's surface. It can be found in continental crust across all geological ages, primarily in ancient cratons and mountain belts.

Uses & Applications

Used extensively in construction for countertops, floor tiles, paving stones, and monuments. Small specimens are collected for geological study.

Geological Facts

Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a massive granite batholith in South Dakota.

Field Identification & Locations

Identify in the field by its interlocking visible crystals of pink/white feldspar and translucent quartz. It is commonly found in mountainous regions or riverbeds near plutonic outcrops.

Identified on: 4/16/2026

Mode: Standard