igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, fine-grained aphanitic texture, dull luster, and high density.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, fine-grained aphanitic texture, dull luster, and high density.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at the Earth's surface.
Uses & applications
Used widely in construction for crushed stone, aggregate in concrete, road base, and manufacturing of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's oceanic crust and also makes up extensive volcanic provinces like the Deccan Traps.
Field identification & locations
Identify in the field by its dark, fine-grained matrix and heavy feel; commonly found globally in volcanic regions and oceanic islands.
