igneous

Granodiorite

Phaneritic intrusive igneous rock (Granodiorite)

Hardness: 6-7 (Mohs scale), Color: Salt-and-pepper (speckled grey-white and black), Luster: Vitreous to dull, Structure: Phaneritic (visible crystals), Composition: Primarily plagioclase feldspar, quartz, and hornblende/biotite.

Identified January 23, 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 cooling of silica-rich magma deep underground. It is an intrusive (plutonic) rock found in batholiths and continental crust, occurring across many geological ages from the Archean to the Cenozoic.

Uses & applications

Extensively used in construction as crushed stone for road base, building stone for monuments and memorials, and polished slabs for kitchen countertops and flooring.

Geological facts

The Rosetta Stone, one of history's most significant archaeological finds, was carved into a slab of granodiorite rather than basalt as originally believed.

Field identification & locations

Identify in the field by its coarse-grained texture and high percentage of white/grey plagioclase feldspar compared to pink potassium feldspar. Commonly found in mountain ranges like the Sierra Nevada in California and the Andes.

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