igneous
Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on Mohs scale, dark grey to black color, aphanitic texture with microscopic crystals, dull to sub-with glassy phases, and specific gravity around 2.9.
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Physical properties
Hardness of 6 on Mohs scale, dark grey to black color, aphanitic texture with microscopic crystals, dull to sub-with glassy phases, and specific gravity around 2.9.
Formation & geological history
Formed from the rapid cooling of low-viscosity basaltic lava exposed at or very near the Earth's surface, common in volcanic regions.
Uses & applications
Widely used in construction as crushed stone for road bases, concrete aggregate, and in the production of rock wool insulation.
Geological facts
Basalt is the most common rock type in the Earth's crust beneath the oceans and also forms massive volcanic structures like the Giant's Causeway.
Field identification & locations
Identify by its dark, fine-grained matrix and heavy weight; extremely common globally in volcanic provinces and compatible with regional geology.
