igneous

Pegmatitic Granite

Granite (Alkali-feldspar granite) with Quartz and Orthoclase

Hardness: 6-7 (Mohs scale); Color: Pink (feldspar) and White/Clear (quartz); Luster: Vitreous to pearly; Crystal structure: Phaneritic/Pegmatitic (large crystals); Cleavage: Perfect in feldspar, none in quartz.

Hardness: 6-7 (Mohs scale)
Color: Pink (feldspar) and White/Clear (quartz)
Luster: Vitreous to pearly

Identified April 5, 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 from the slow cooling of magma deep underground, often in the late stages of a pluton's crystallization where mineral-rich fluids facilitate large crystal growth.

Uses & applications

Commonly used as crushed stone in construction, dimension stone for countertops and tiles, and as a source for extracting specific minerals like feldspar or mica.

Geological facts

This specimen contains Orthoclase feldspar, which gets its pink color from trace amounts of iron or potassium within the crystal lattice. Large-grained granite is often called pegmatite if the grains are larger than 2.5 cm.

Field identification & locations

Identify by looking for intergrown crystals of pink feldspar and glassy quartz. Found worldwide in continental crust, particularly in mountain belts and ancient shield areas like the Appalachians or the Canadian Shield.

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