Rock Identifier
Granite (Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)) — igneous
igneous

Granite

Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Hardness: 6-7 on Mohs scale. Color: Generally pink, white, or gray with dark specks. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained coarse crystals visible to the naked eye). Cleavage: Varies by mineral constituent (feldspar has 2 planes). Specific gravity: 2.63 to 2.75.

Hardness
6-7 on Mohs scale
Color
Generally pink, white, or gray 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: Generally pink, white, or gray with dark specks. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained coarse crystals visible to the naked eye). Cleavage: Varies by mineral constituent (feldspar has 2 planes). Specific gravity: 2.63 to 2.75.

Formation & geological history

Formed from the slow crystallization of magma below Earth's surface (plutonic). Typically found in continental crust and can range from Precambrian to Cenozoic geological ages.

Uses & applications

Extensively used in construction for countertops, floor tiles, paving stone, curbing, and monuments. Also used as crushed stone or aggregate in road building and concrete.

Geological facts

Granite is the most common igneous rock found on Earth's continents. The term comes from the Latin 'granum', meaning a grain, referring to its coarse-grained structure. Mount Rushmore is carved into a granite batholith.

Field identification & locations

Identify in the field by its 'salt and pepper' appearance and visible interlocking crystals of quartz and feldspar. Commonly found in mountain ranges and glacial till. Collectors look for unique mineral inclusions like garnet or tourmaline.

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

Blue Apatite

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

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

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral
Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

mineral