igneous

Granite

Granite (Felsic Plutonic Rock)

Hardness: 6-7 on Mohs scale. Color: Pinkish-gray with white, black, and translucent grains. Luster: Dull to vitreous. Structure: Phaneritic (coarse-grained) crystalline. Cleavage: None (the minerals within it like mica and feldspar may show cleavage individually).

Hardness: 6-7 on Mohs scale
Color: Pinkish-gray with white, black, and translucent grains
Luster: Dull to vitreous

Identified April 12, 2026More igneous →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the slow crystallization of magma below Earth's surface (intrusive). Often found in continental crust and mountain ranges, dating from the Archean to the Cenozoic era.

Uses & applications

Extensively used in construction (countertops, floor tiles), monuments, paving stones, and as crushed stone for road aggregate.

Geological facts

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

Field identification & locations

Identify by its interlocking 'salt and pepper' appearance of pink/white feldspar, translucent quartz, and dark biotite or hornblende grains. Common in glacial till and landscaping beds.

Other igneous specimens

See all

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous