Granite

Physical Properties

Hardness: 6-7 Mohs; Color: Salt and pepper (white, grey, black); Luster: Vitreous to pearly; Crystal structure: Phaneritic (coarse-grained); Cleavage: Indistinct; Specific gravity: 2.63-2.75.

Formation & Geological History

Formed by the slow crystallization of magma below the Earth's surface (intrusive). The cooling process can take millions of years, allowing large crystals to form within continental crust environments.

Uses & Applications

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

Geological Facts

Granite is one of the most common rocks on the Earth's continental crust. It forms the core of many mountain ranges and is a primary component of the Yosemite National Park landscape.

Field Identification & Locations

Identify in the field by its interlocking coarse crystals of quartz (clear/grey) and feldspar (white/pink) with flecks of biotite or hornblende (black). It is found globally in continental shield areas.

Identified on: 5/1/2026

Mode: Standard