Peridot (Olivine)

Physical Properties

Hardness: 6.5-7.0 on Mohs scale; Color: Olive-green, yellow-green; Luster: Vitreous (glassy); Crystal Structure: Orthorhombic; Cleavage: Poor; Specific Gravity: 3.2-3.4

Formation & Geological History

Formed deep in the Earth's mantle and brought to the surface by volcanic activity in basaltic rocks. It is one of the few gemstones that occur in only one color. Can also be found in pallasite meteorites.

Uses & Applications

Primarily used as a gemstone in jewelry (birthstone for August). Also studied for insights into mantle composition.

Geological Facts

Peridot is often called the 'Evening Emerald' because it glows brilliantly under artificial light. It has been found in comet dust and meteorites from outer space.

Field Identification & Locations

Identify by its distinctive oily-green color and lack of multiple colors (pleochroism). Commonly found in Arizona (USA), Myanmar, Pakistan, and Egypt. Collectors look for high clarity and rich 'lime' saturation.

Identified on: 5/2/2026

Mode: Standard