Peridot

Physical Properties

Hardness: 6.5–7.0 (Mohs); Color: Olive-green, yellow-green; Luster: Vitreous; Crystal Structure: Orthorhombic; Cleavage: Poor; Specific Gravity: 3.27–3.37

Formation & Geological History

Formed deep within the Earth's mantle and brought to the surface by volcanic activity. Also found in Pallasite meteorites from outer space. Generally occurs in silica-poor igneous rocks like basalt.

Uses & Applications

Primarily used as a gemstone in jewelry (rings, necklaces, earrings). Historically used as a protective talisman and in decorative religious objects.

Geological Facts

Peridot is one of the few gemstones that occurs in only one color: green. Some specimens have extraterrestrial origins, having been recovered from meteorites that crashed into Earth. It is the birthstone for August.

Field Identification & Locations

Identify by its distinctive lime-green color and double refraction (doubling of back facets when viewed through the front). In the field, it is often found as small grains in basalt or within 'olivine bombs' near volcanic sites like San Carlos, Arizona.

Identified on: 4/14/2026

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