igneous

Granite

Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)

Hardness: 6-7 on Mohs scale; Color: Phaneritic (visible grains) mixture of white, gray, and black minerals; Luster: Dull to vitreous; Crystal structure: Crystalline/Massive; Cleavage: None (grains have individual cleavage); Specific gravity: 2.63 - 2.75.

Hardness: 6-7 on Mohs scale
Luster: Dull to vitreous

Identified March 19, 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 (intrusive). It typically forms in continental crust during mountain-building events and can range from millions to billions of years old.

Uses & applications

Extensively used in construction for countertops, floor tiles, paving stones, and monuments due to its durability and resistance to weathering.

Geological facts

Granite makes up a large part of the Earth's continental crust. Famous landmarks like Mount Rushmore and Yosemite's Half Dome are carved from or composed of massive granite formations.

Field identification & locations

Identify in the field by its 'salt and pepper' appearance and large, interlocking mineral grains. It is found in mountain ranges and Shields (like the Canadian Shield). Collectors look for specimens with large crystals or unique accessory minerals like Garnet.

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