igneous
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
Hardness: 6-7 (Mohs). Color: Dark grey to black matrix with yellowish-green crystalline pockets. Luster: Dull to vitreous. Structure: Aphanitic (fine-grained) matrix with granular inclusions. Specific Gravity: 2.8 - 3.4.
- Hardness
- 6-7 (Mohs)
- Luster
- Dull to vitreous
Identified More igneous →
Explore Basalt with Peridotite Inclusion in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs). Color: Dark grey to black matrix with yellowish-green crystalline pockets. Luster: Dull to vitreous. Structure: Aphanitic (fine-grained) matrix with granular inclusions. Specific Gravity: 2.8 - 3.4.
Formation & geological history
Formed from the rapid cooling of magnesium-rich and iron-rich lava. The green inclusion (xenolith) is a piece of the Earth's mantle caught in the magma as it rose to the surface during a volcanic eruption.
Uses & applications
Basalt is used extensively in construction for aggregate, road base, and concrete. The peridotite (olivine) within it is used as a gemstone (peridot) when high quality, and industrially for refractory materials.
Geological facts
Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floor. The green inclusions (xenoliths) provide geologists with rare direct samples of the Earth's upper mantle from miles deep.
Field identification & locations
Identify in the field by its heavy weight and dark, fine-grained appearance. Look for 'glassy' green crystals embedded in a dark stone. Common in volcanic regions like Hawaii, Iceland, and the Canary Islands.
