Peridot

Physical Properties

Hardness: 6.5–7 (Mohs scale); Color: Olive-green, yellowish-green; Luster: Vitreous (glassy); Crystal structure: Orthorhombic; Cleavage: Poor; Specific gravity: 3.27–3.37

Formation & Geological History

Formed deep in the Earth's mantle and brought to the surface by volcanic activity in basaltic rocks; can also be found in pallasite meteorites.

Uses & Applications

Primarily used as a gemstone in jewelry; historically used as a protective talisman; the birthstone for August.

Geological Facts

Peridot is one of the few gemstones that occurs in only one color. It has been found in meteorites, meaning it exists in outer space, and some were discovered on Mars by the Curiosity rover.

Field Identification & Locations

Identify by its distinctive 'oily' green color and strong double refraction (doubling of back facets when viewed through the table). Commonly found in zeolite-bearing basalts or alluvial deposits.

Identified on: 4/27/2026

Mode: Standard