peridotite
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Definition
- Noun:
- A dark coarse-grained igneous rock consisting principally of olivine: Peridotite is a dense, heavy rock that forms deep within the Earth's mantle. It is composed mostly of the mineral olivine, along with other minerals like pyroxene and amphibole. It is the primary source rock for the gemstone peridot.
Usage Examples
- Noun:
- The geologist identified the sample as peridotite based on its coarse texture and greenish minerals.
- Peridotite is thought to be the dominant rock of the Earth's upper mantle.
- Diamonds are sometimes found in pipes of peridotite that have erupted from great depths.
Advanced Usage
- "Peridotite xenolith": A fragment of peridotite rock that is carried to the Earth's surface by a volcanic eruption without melting. It provides direct samples of the mantle.
- The volcano's lava contained numerous peridotite xenoliths, offering a rare glimpse into the mantle's composition.
Variants and Related Words
- Peridot (n): A clear, yellowish-green gemstone variety of the mineral olivine, which is the main component of peridotite.
- Her ring was set with a beautiful peridot.
- Dunite (n): A type of peridotite composed almost entirely of olivine.
- Kimberlite (n): A rare, volatile-rich variety of peridotite that is a primary host rock for diamonds.
Synonyms
- Ultramafic rock: A technical term for igneous rocks with very low silica content and rich in magnesium and iron minerals, which includes peridotite.
- Mantle rock: A general term for rocks believed to constitute the Earth's mantle, primarily peridotite.
Related Concepts
- Serpentinization: A geological process where peridotite reacts with water to form serpentinite, a softer, green rock.
- The peridotite had undergone serpentinization, altering its original mineral structure.
- Igneous rock: The broad category of rocks formed from the cooling and solidification of magma or lava, to which peridotite belongs.
Noun
- a dark coarse-grained igneous rock consisting principally of olivine