igneous

Granite

Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O, Na2O)

Hardness: 6-7 on Mohs scale; Color: typically mottled pink, white, gray, and black; Luster: vitreous to dull; Crystal Structure: phaneritic (visible coarse-grained crystals); Cleavage: none (irregular fracture); Specific Gravity: 2.63 to 2.75

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

Identified March 20, 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). Geological age varies widely from Archean to recent, depending on the specific pluton.

Uses & applications

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

Geological facts

Granite makes up a large portion of the Earth's continental crust. Mount Rushmore is carved into a granite batholith. It is one of the hardest and most durable common stones on the planet.

Field identification & locations

Identified in the field by its 'salt and pepper' appearance and interlocking visible crystals of quartz, feldspar, and mica. Found globally in mountainous regions and exposed shields. Collectors look for unique vein patterns or large phenocrysts (porphyritic texture).

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