igneous

Granite

Granitoid (comprised of Quartz, Feldspar, and Mica)

Hardness: 6-7 Mohs; Color: Pink, light gray, or white with dark flecks; Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained); Specific gravity: 2.63-2.75

Hardness: 6-7 Mohs
Color: Pink, light gray, or white with dark flecks
Luster: Dull to vitreous

Identified May 23, 2026More igneous →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6-7 Mohs; Color: Pink, light gray, or white with dark flecks; Luster: Dull to vitreous; Crystal structure: Phaneritic (coarse-grained); Specific gravity: 2.63-2.75

Formation & geological history

Formed through the slow crystallization of magma below Earth's surface. Found in continental crust within mountain ranges or batholiths formed across various geological eras.

Uses & applications

Widely used in construction for countertops, floor tiles, paving stones, monuments, and as crushed stone for road base.

Geological facts

Granite makes up a large part of the Earth's continental crust. It is one of the hardest and most durable common stones, which is why it has been used since ancient Egypt for building pyramids and temples.

Field identification & locations

Identify in the field by its interlocking visible crystals. It is found in mountain belts and shield areas like the Rockies, Appalachians, or Canadian Shield. Collectors look for unique mineral inclusions like large tourmaline or garnets.

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

Blue Apatite

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

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Magnetite

Magnetite (Fe3O4)

mineral