igneous
Basalt
Mafic extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, and dull luster.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, aphanitic texture, and dull luster.
Formation & geological history
Formed from the rapid cooling of low-viscosity, magnesium- and iron-rich lava flows at the Earth's surface.
Uses & applications
Commonly used in construction as crushed stone for road bases, concrete aggregate, and dimension stone.
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 in the field by its dark, fine-grained matrix and vesicular structures from trapped gas bubbles.
