Peridot
Olivine (Mg, Fe)2SiO4
Rock Type: mineral

Physical Properties
Hardness: 6.5–7.0 (Mohs scale); Color: Olive-green to lime-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. It is one of the few gemstones that occurs in only one color. It is also found in pallasite meteorites.
Uses & Applications
Primarily used as a gemstone in jewelry (rings, necklaces, earrings). It is the birthstone for August.
Geological Facts
Ancient Egyptians called Peridot the 'gem of the sun.' It has been found in comet dust from the Stardust robotic spacecraft. It is the only gemstone found in meteorites that is large enough to be worn as jewelry.
Field Identification & Locations
Identify by its distinctive olive-green color and high birefringence (doubling of back facets). Commonly found in basaltic rocks, San Carlos Apache Reservation in Arizona, Pakistan, and Myanmar.
Identified on: 4/14/2026
Mode: Standard