Olivine (Peridot)

Physical Properties

Hardness: 6.5-7 Mohs; Color: Olive-green, yellow-green; Luster: Vitreous; Crystal Structure: Orthorhombic; Cleavage: Poor; Specific Gravity: 3.27-4.37.

Formation & Geological History

Formed in the Earth's upper mantle and brought to the surface through volcanic activity; commonly found in mafic and ultramafic igneous rocks like basalt and peridotite.

Uses & Applications

Used primarily as a gemstone (Peridot) in jewelry. Also used as a refractory material in steel making, as a casting sand, and as an abrasive.

Geological Facts

Olivine is one of the most common minerals in Earth's mantle and has also been discovered in lunar rocks and many meteorites (pallasites). Its gem-quality name is Peridot.

Field Identification & Locations

Identify by its distinctive olive-green color and lack of perfect cleavage. Often found as small, glassy grains in basalt lava or dark volcanic rocks in regions like Arizona or Hawaii.

Identified on: 4/18/2026

Mode: Standard