Peridot

Physical Properties

Hardness: 6.5-7 (Mohs); Color: Lime green, olive green, yellowish green; Luster: Vitreous (glassy); Crystal Structure: Orthorhombic; Cleavage: Poor; Specific Gravity: 3.2-4.3

Formation & Geological History

Formed deep in the Earth's mantle and brought to the surface by volcanic activity in igneous rocks like basalt. Some specimens have been found in pallasite meteorites.

Uses & Applications

Primarily used as a gemstone in jewelry; it is the birthstone for August. Industrial grades are used as slag conditioners in metallurgy.

Geological Facts

Known as the 'Evening Emerald' due to its ability to maintain its brilliant green color even under artificial light. It is one of the few gemstones that occurs in only one color.

Field Identification & Locations

Identified by its signature lime-green color and double refraction (doubling of back facets when viewed through the table). Commonly found in Arizona (USA), Pakistan, and Myanmar.

Identified on: 4/14/2026

Mode: Standard