igneous

Granite

Phaneritic Felsic Igneous Rock

Hardness: 6-7 (Mohs scale); Color: Salt and pepper (pinkish-brown and black grains); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: None (minerals within exhibit cleavage independently); Specific gravity: 2.63 - 2.75

Hardness: 6-7 (Mohs scale)
Color: Salt and pepper (pinkish-brown and black grains)
Luster: Vitreous to dull

Identified March 8, 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 the Earth's surface (intrusive). The large grains indicate a long cooling period. It can date back over 4 billion years in the Earth's crust.

Uses & applications

Extensively used in construction for countertops, floor tiles, paving stones, curbing, monuments, and as aggregate for roads.

Geological facts

Granite makes up a large portion of the Earth's continental crust. Famous locations like Yosemite's Half Dome and Mount Rushmore are made entirely of granite.

Field identification & locations

Identify in the field by its visible interlocking crystals of quartz (clear/grey), feldspar (tan/pink), and mica (black/shiny). It is commonly found in mountain ranges and continental shields. Collectors look for unique mineral inclusions like tourmaline or large feldspar crystals.

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