igneous
Basalt
Extrusive mafic igneous rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, and high specific gravity around 2.9.
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Physical properties
Hardness of 6 on the Mohs scale, dark gray to black color, aphanitic texture, dull luster, and high specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at the Earth's surface.
Uses & applications
Widely used in construction for crushed stone, road base, asphalt aggregate, and in manufacturing stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's oceanic crust and also makes up extensive volcanic plains on the Moon and Mars.
Field identification & locations
Identify by its dark, fine-grained matrix and heavy weight; commonly found globally in volcanic regions and oceanic islands.
