Granite

Physical Properties

Hardness: 6-7 (Mohs scale), Color: Pinkish-tan with black and gray speckles, Luster: Vitreous to pearly, Crystal structure: Phaneritic (coarse-grained), Cleavage: None (though minerals within it have cleavage), Specific gravity: 2.65-2.75

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface. It is typical of continental crust and can date back billions of years (Archean era to Cenozoic).

Uses & Applications

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

Geological Facts

Granite makes up a large part of the continental crust. Half Dome in Yosemite National Park is a massive granite monolith. It is one of the hardest substances in the world, second only to diamonds.

Field Identification & Locations

Identify in the field by its interlocking coarse grains of quartz (translucent), feldspar (opaque/pink/white), and mica or hornblende (black). It is found in mountain ranges and Shields (like the Canadian Shield).

Identified on: 4/22/2026

Mode: Standard