igneous

Granite

Granite (Felsic Plutonic Rock)

Hardness: 6-7 (Mohs scale); Color: Mottled grey, white, and black with visible crystals; Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: Indistinct; Specific gravity: 2.63-2.75.

Hardness: 6-7 (Mohs scale)
Color: Mottled grey, white, and black with visible crystals
Luster: Vitreous to dull

Identified March 25, 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. It is a plutonic rock that cools over thousands to millions of years, allowing large mineral crystals to grow. Found in continental crust ranging from Precambrian to Cenozoic ages.

Uses & applications

Primary use in construction as dimension stone (countertops, flooring, monuments), aggregate for road base, and decorative landscaping. It is also a popular specimen for educational geology kits.

Geological facts

Granite is the most common rock in Earth's continental crust and is what makes up the core of many major mountain ranges. The famous El Capitan in Yosemite National Park is a massive monolith of granite.

Field identification & locations

Identify in the field by its speckled, 'salt and pepper' appearance and visible interlocking crystals of quartz, feldspar, and mica. Commonly found in mountainous regions or areas with exposed batholiths. It will not scratch with a copper penny but will scratch glass.

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