igneous
Peridotite (with Olivine)
Peridotite (dominantly (Mg, Fe)2SiO4)
Hardness: 6.5-7.0 (Olivine); Color: Olive-green to lime-green with brownish-red crust; Luster: Vitreous to dull; Crystal structure: Orthorhombic; Specific gravity: 3.2-3.4
- Hardness
- 6
- Color
- Olive-green to lime-green with brownish-red crust
- Luster
- Vitreous to dull
Identified More igneous →
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Physical properties
Hardness: 6.5-7.0 (Olivine); Color: Olive-green to lime-green with brownish-red crust; Luster: Vitreous to dull; Crystal structure: Orthorhombic; Specific gravity: 3.2-3.4
Formation & geological history
Ultramafic igneous rock formed in the Earth's mantle through slow cooling of magma at high temperatures and pressures. Often brought to the surface via volcanic pipes or tectonic activity.
Uses & applications
Primary source of the gemstone peridot; also used in carbon sequestration research and as an industrial refractory material due to high melting point.
Geological facts
Peridotite is the dominant rock of the upper part of the Earth's mantle; it is rarely seen on the surface because it is chemically unstable and easily weathers into serpentine.
Field identification & locations
Identified by its signature dense, sugary texture and distinct green color. Common in ophiolites and xenoliths within basalt. Collectors look for bright green vitreous grains within the darker matrix.
