igneous
Basalt
Extrusive igneous rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark gray to black color, dull to sub-metamorphic luster, aphanitic texture with microscopic crystals, and high specific gravity around 2.9.
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Physical properties
Hardness of 6 on Mohs scale, dark gray to black color, dull to sub-metamorphic luster, aphanitic texture with microscopic crystals, 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 or ocean floor.
Uses & applications
Widely used in construction as crushed aggregate for roads, railroad ballast, and in the production of stone wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust, underlying most ocean basins and forming massive geological features like the Columbia River Plateaus.
Field identification & locations
Identified by its fine-grained dark appearance and dense, heavy weight; commonly found in volcanic regions worldwide.
