igneous

Granite

Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)

Hardness: 6-7 on Mohs scale; Color: typically mottled white, gray, pink, and black; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained) with visible crystals of quartz, feldspar, and mica; Cleavage: none (cleaved mica within the matrix may show planar cleavage).

Hardness: 6-7 on Mohs scale
Color: typically mottled white, gray, pink, and black
Luster: Vitreous to dull

Identified March 23, 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 the Earth's surface (plutonic). Found in continental crust, often dating back hundreds of millions to billions of years, formed during orogenic (mountain-building) events.

Uses & applications

Extensively used in construction as dimension stone for countertops, flooring, and curbing. Also used as crushed stone for road base and aggregate in concrete.

Geological facts

Granite makes up the majority of the Earth's continental crust. Famous landmarks like Mount Rushmore and Yosemite's El Capitan are composed entirely of granite.

Field identification & locations

Identify by its 'salt and pepper' appearance and visible interlocking crystals. Common in mountain ranges and shield regions. Look for hard, scratch-resistant surfaces with blocky feldspar and glassy quartz grains.

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

Magnetite

Iron(II,III) oxide (Fe3O4)

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Magnetite

Magnetite (Fe3O4)

mineral