igneous

Granite

Granite (Phaneritic Quartz-Feldspar Felsic Rock)

Hardness: 6-7 on Mohs scale; Color: Salt-and-pepper (white, grey, and black); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained crystals visible to the naked eye); Cleavage: Indistinct in the rock overall, though individual mica/feldspar grains may show it; Specific gravity: 2.65 to 2.75.

Hardness: 6-7 on Mohs scale
Color: Salt-and-pepper (white, grey, and black)
Luster: Vitreous to dull

Identified January 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 by the slow crystallization of magma below Earth's surface (intrusive). It is predominantly found in the continental crust and forms in large masses called batholiths. It exists across all geological ages, from the Precambrian to Cenozoic.

Uses & applications

Extensively used in construction for countertops, floor tiles, paving stones, and curbing. It is also used in monuments, bridges, and as crushed stone for road base and railroad ballast. Highly valued in landscaping and architecture for its durability.

Geological facts

Granite makes up a large part of the continental crust. Because it is so hard and durable, it was the preferred building material for the ancient Egyptian pyramids' inner chambers and many of the world's most enduring monuments. It is the signature rock of the continents, as it is rarely found on the ocean floor.

Field identification & locations

Identify in the field by its interlocking coarse crystals and 'speckled' appearance. Look for the presence of translucent quartz, opaque white or pink feldspar, and black specks of mica or hornblende. It is found globally in mountainous regions where deep-seated igneous rocks have been exposed by erosion (e.g., the Sierra Nevada, the Alps, or the Scottish Highlands).

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