igneous

Granitoid (Granite/Granodiorite)

Plutonic igneous rock (variable composition, primarily SiO2)

Hardness: 6-7 on Mohs scale; Color: Salt-and-pepper (grey, white, black, tan); Luster: Phaneritic (crystalline/sparkly); Structure: Massive, phaneritic grain texture; Specific Gravity: 2.63 - 2.75

Hardness: 6-7 on Mohs scale
Color: Salt-and-pepper (grey, white, black, tan)
Luster: Phaneritic (crystalline/sparkly)

Identified April 11, 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 on Mohs scale; Color: Salt-and-pepper (grey, white, black, tan); Luster: Phaneritic (crystalline/sparkly); Structure: Massive, phaneritic grain texture; Specific Gravity: 2.63 - 2.75

Formation & geological history

Formed through the slow crystallization of magma beneath the Earth's surface (intrusive). This specimen likely dates back to regional mountain-building events, often occurring millions of years ago.

Uses & applications

Commonly used in heavy construction, road base, countertops, monuments, and as crushed stone for landscaping.

Geological facts

Granite makes up the majority of the Earth's continental crust. It is one of the hardest natural stones available, and the famous faces on Mount Rushmore are carved into a granite batholith.

Field identification & locations

Identify by its 'salt and pepper' look where you can see individual interlocking crystals of quartz, feldspar, and mica. It is found in the cores of mountain ranges and shield areas. Collectors value specimens with unique mineral inclusions or rare colors.

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