Rock Identifier
Granite (Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)) — igneous
igneous

Granite

Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)

Hardness: 6-7 on Mohs scale. Color: Mottled grey, white, pink, or red with dark specks. Luster: Vitreous to dull. Crystal Structure: Phaneritic (visible coarse-grained crystals). Cleavage: Varies by mineral content (feldspar has two, quartz has none). Specific Gravity: 2.63 to 2.75.

Hardness
6-7 on Mohs scale
Color
Mottled grey, white, pink, or red with dark specks
Luster
Vitreous to dull
Identified More igneous →

Identify your own rocks.

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

App StoreGoogle Play

Physical properties

Hardness: 6-7 on Mohs scale. Color: Mottled grey, white, pink, or red with dark specks. Luster: Vitreous to dull. Crystal Structure: Phaneritic (visible coarse-grained crystals). Cleavage: Varies by mineral content (feldspar has two, quartz has none). Specific Gravity: 2.63 to 2.75.

Formation & geological history

Formed from the slow crystallization of silica-rich magma beneath the Earth's surface (plutonic). It is found primarily in the continental crust and can range in age from the Precambrian to the Cenozoic eras.

Uses & applications

Extensively used as a dimension stone for countertops, flooring, and monuments due to its durability. Also used as crushed stone (aggregate) for road construction and foundations.

Geological facts

Granite makes up the majority of the Earth's continental crust. Famous natural formations like Yosemite's Half Dome and Mount Rushmore are composed of granite. It is one of the hardest and most common rocks on the planet.

Field identification & locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of different colors. It is found in mountain ranges and continental shields. Collectors look for large crystals or unusual mineral inclusions.

More like this

Other igneous specimens

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

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

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

Magnetite

Iron(II,III) oxide (Fe3O4)

mineral
Sodalite (Sodalite - Na8(Al6Si6O24)Cl2) — mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral
Blue Apatite (Apatite (Group), Ca5(PO4)3(F,Cl,OH)) — mineral

Blue Apatite

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

mineral
Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

mineral