mineral

Olivine (Peridotite / Dunite Pebble)

(Mg,Fe)2SiO4 (Magnesium Iron Silicate)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale. Color: Olive-green to yellowish-green with a frosted, water-worn surface. Luster: Vitreous to dull. Crystal Structure: Orthorhombic. Specific Gravity: 3.2-4.4.

Hardness: 6
Luster: Vitreous to dull

Identified July 25, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale. Color: Olive-green to yellowish-green with a frosted, water-worn surface. Luster: Vitreous to dull. Crystal Structure: Orthorhombic. Specific Gravity: 3.2-4.4.

Formation & geological history

Formed in ultramafic igneous rocks such as dunite, peridotite, and basalt within Earth's mantle, then exposed at the surface and tumbled smooth by river or beach erosion.

Uses & applications

Used as a gemstone (Peridot) when gem-quality, as a refractory material in metallurgy, for CO2 sequestration studies, and for lapidary collection.

Geological facts

Olivine is one of the primary components of the Earth's upper mantle and is also found in stony meteorites (pallasites) and on the surface of the Moon and Mars.

Field identification & locations

Identified by its distinctive olive-green color, grainy granular texture, and glass-like hardness. Common in basaltic beach sands (like Green Sand Beach in Hawaii) and volcanic areas.