Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Salt-and-pepper look with pink/tan, white, and black; Luster: Vitreous to dull; Structure: Phaneritic (coarse-grained) crystalline; Cleavage: None (grains display individual mineral cleavage); Specific Gravity: 2.63 to 2.75

Formation & Geological History

Formed through the slow crystallization of felsic magma beneath the Earth's surface (plutonic). They are found in continental crust across all geological ages, often forming the cores of mountain ranges.

Uses & Applications

Extensively used in construction as dimension stone, countertops, flooring, and road base/aggregate. Also used for monuments and decorative carvings.

Geological Facts

Granite is the most common igneous rock found on Earth's continents. The iconic peaks of Yosemite National Park and the faces of Mount Rushmore are carved into granite formations.

Field Identification & Locations

Identify by its 'salt and pepper' appearance and visible interlocking crystals of quartz (glassy gray), feldspar (white/pink), and biotite or hornblende (black). It is a key component of the continental crust.

Identified on: 4/29/2026

Mode: Standard