Olivine (Peridot)

Physical Properties

Hardness: 6.5–7 on the Mohs scale. Color: Olive-green to brownish-green. Luster: Vitreous (glassy). Crystal Structure: Orthorhombic. Cleavage: Poor. Specific Gravity: 3.27–4.37.

Formation & Geological History

Formed in the Earth's mantle and brought to the surface by tectonic or volcanic activity. It is a major component of igneous rocks like basalt and gabbro. Most specimens date back millions to billions of years.

Uses & Applications

Used primarily as a gemstone (Peridot) in jewelry. Industrially, it is used as a flux for steel production, in foundry sand, and as a refractory material in furnace linings.

Geological Facts

Olivine is one of the most common minerals in the Earth's interior and has even been identified in meteorites (Pallasites) and on Mars and the Moon.

Field Identification & Locations

Identify by its distinctive olive-green color and glassy appearance. Unlike quartz, it has poor cleavage and is usually found in granular masses. Commonly found in volcanic regions like Hawaii, Arizona, or Norway.

Identified on: 4/28/2026

Mode: Standard