igneous

Olivine (Peridotite)

Olivine Group; (Mg, Fe)2SiO4

Hardness: 6.5-7 (Mohs scale); Color: Olive-green, lime-green, or brownish-green; Luster: Vitreous (glassy); Crystal Structure: Orthorhombic; Specific Gravity: 3.2-4.4

Hardness: 6
Color: Olive-green, lime-green, or brownish-green
Luster: Vitreous (glassy)

Identified March 29, 2026More igneous →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Olive-green, lime-green, or brownish-green; Luster: Vitreous (glassy); Crystal Structure: Orthorhombic; Specific Gravity: 3.2-4.4

Formation & geological history

Formed in the Earth's upper mantle and brought to the surface by volcanic eruptions of basaltic lavas or within ultramafic igneous rocks like peridotite or dunite.

Uses & applications

Used as a refractory material in steel making (sand casting), as a gemstone (Peridot) for jewelry, and occasionally as an abrasive or decorative landscaping stone.

Geological facts

Olivine is one of the most common minerals in the Earth's upper mantle. It is also found in meteorites (Pallasites), which can contain beautiful, translucent olivine crystals trapped in a nickel-iron matrix.

Field identification & locations

Identify by its distinctive pistachio to olive-green color and sugary, granular texture in coarse-grained rocks. Common in volcanic regions (Hawaii) or tectonic suture zones. It lacks a clear cleavage, often showing conchoidal fracture.

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