Peridot

Physical Properties

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

Formation & Geological History

Formed deep within the Earth's mantle and brought to the surface by volcanic eruptions. It is one of the few gemstones that occurs in only one color. Some peridot specimens (pallasites) have also been found in meteorites.

Uses & Applications

Primarily used as a gemstone in jewelry (rings, necklaces, earrings). It is the birthstone for August.

Geological Facts

Known by Ancient Egyptians as the 'gem of the sun.' It is sometimes found in volcanic sands, such as Papakolea Beach in Hawaii. Peridot found in meteorites is incredibly rare and is known as 'extraterrestrial peridot.'

Field Identification & Locations

Identify in the field by its distinct lime-green color and lack of multiple colors (pleochroism). In the field, it is often found as grains in basaltic rocks. Collectors look for high clarity and lack of 'lily pad' inclusions.

Identified on: 4/25/2026

Mode: Standard