Peridot

Physical Properties

Hardness: 6.5–7 on the Mohs scale; Color: Lime, olive, or yellowish-green; Luster: Vitreous (glassy); Crystal structure: Orthorhombic; Cleavage: Poor; Specific gravity: 3.2–4.3.

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. Its formation dates back millions to billions of years depending on the deposit.

Uses & Applications

Primarily used as a gemstone in jewelry (birthstone for August). Historically used in talismans and decorative religious items.

Geological Facts

Peridot is one of the few gemstones that occurs in only one color: green. It has been found in stardust brought back from a robotic space probe and in meteorites, making it an 'extraterrestrial' gem in some instances.

Field Identification & Locations

Identify by its distinctive 'oily' or olive-green color and strong double refraction. Commonly found in basaltic rocks, particularly in Arizona (USA), Myanmar, Pakistan, and the Red Sea (St. John's Island).

Identified on: 4/15/2026

Mode: Standard