Peridot (Olivine)

Physical Properties

Hardness: 6.5-7 Mohs; Color: Olive-green to lime; Luster: Vitreous; Crystal Structure: Orthorhombic; Cleavage: Poor; Specific Gravity: 3.27-3.37

Formation & Geological History

Peridot is formed deep in the Earth's mantle and brought to the surface by volcanic activity. It is one of the few gemstones that occurs in only one color and can also be found in certain types of meteorites (pallasites).

Uses & Applications

Primarily used as a gemstone in jewelry such as rings, necklaces, and earrings. It is also the birthstone for August and has significant value for mineral collectors.

Geological Facts

Peridot is sometimes called the 'Evening Emerald' because it maintains its brilliant green color even under artificial light. It has been found in the dust of comets and in meteorites over 4 billion years old.

Field Identification & Locations

Identified in the field by its distinct oily green color and lack of reaction to acid. It is commonly found in basaltic rocks, particularly in locations like Arizona (San Carlos Reservation), Egypt (St. John's Island), and Myanmar.

Identified on: 5/7/2026

Mode: Standard