igneous
Olivine Weathered Rock (Dunite)
Dunite ((Mg, Fe)2SiO4)
Hardness: 6.5-7. Color: Olive-green to yellowish-brown when weathered. Luster: Vitreous to dull. Crystal structure: Orthorhombic. Specific gravity: 3.2-4.5.
- Hardness
- 6
- Color
- Olive-green to yellowish-brown when weathered
- Luster
- Vitreous to dull
Identified More igneous →
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Physical properties
Hardness: 6.5-7. Color: Olive-green to yellowish-brown when weathered. Luster: Vitreous to dull. Crystal structure: Orthorhombic. Specific gravity: 3.2-4.5.
Formation & geological history
An ultramafic igneous rock formed deep in the Earth's mantle and brought to the surface through tectonic processes. It is composed of at least 90% olivine.
Uses & applications
Used as a refractory material in steel making, as a casting sand, and as a source of magnesium. Some high-quality specimens are used as gemstones (peridot).
Geological facts
Dunite is the major constituent of the Earth's upper mantle. The green coloring is characteristic of high-magnesium olivine content.
Field identification & locations
Identify by its distinctive olive-green color and grainy, crystalline texture. It is often found in ophiolite complexes and as xenoliths in basalt flows.
