igneous
Peridotite
Peridotite (composed largely of olivine (Mg,Fe)2SiO4 and pyroxene)
Hardness: 6.5-7.0 (Olivine); Color: Olive-green to dark green; Luster: Dull to vitreous; Crystal structure: Orthorhombic; Specific gravity: 3.2-3.4; Coarse-grained texture.
- Hardness
- 6
- Color
- Olive-green to dark green
- Luster
- Dull to vitreous
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Physical properties
Hardness: 6.5-7.0 (Olivine); Color: Olive-green to dark green; Luster: Dull to vitreous; Crystal structure: Orthorhombic; Specific gravity: 3.2-3.4; Coarse-grained texture.
Formation & geological history
Formed in the Earth's upper mantle through the slow cooling and crystallization of ultramafic magma. It is a major constituent of the Earth's mantle and is often brought to the surface through tectonic processes or volcanic pipes.
Uses & applications
The primary source of the gemstone peridot; used in industry for carbon sequestration research and as an ornamental stone.
Geological facts
Peridotite is most famous for being the primary component of the Earth's mantle. It is classified as an ultramafic rock, meaning it contains less than 45% silica and is rich in magnesium and iron.
Field identification & locations
Identify by its characteristic olive-green color and granular, crystalline texture. Commonly found in ophiolites, xenoliths in basalt, and in the roots of mountain ranges.
