Granite

Physical Properties

Hardness: 6-7 on Mohs scale; Color: typically grayish, pinkish, or white; Luster: vitreous to dull; Structure: phaneritic (visible crystals); Cleavage: none (fractures irregularly); Specific gravity: 2.63 - 2.75

Formation & Geological History

Formed from the slow crystallization of magma below Earth's surface (intrusive). Most granites date from the Precambrian or Paleozoic eras and are found in the continental crust.

Uses & Applications

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

Geological Facts

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

Field Identification & Locations

Identify by looking for interlocked crystals of quartz (glassy gray), feldspar (opaque white/pink), and mica (shiny black flakes). It is found globally in mountainous regions or where ancient shields are exposed.

Identified on: 4/20/2026

Mode: Standard