igneous
Basalt
Basalt
AI-generated identification · may be incorrectDark colored, fine-grained, heavy for its size. Hardness 5.5-6 on Mohs scale. Opaque with a dull luster when dry, but appears shiny when wet.
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Physical properties
Dark colored, fine-grained, heavy for its size. Hardness 5.5-6 on Mohs scale. Opaque with a dull luster when dry, but appears shiny when wet.
Formation & geological history
Formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon.
Uses & applications
Used in construction, as aggregate, in cobblestones, and sometimes in sculpture. Also collected as river stones or beach stones.
Geological facts
Basalt is the most common volcanic rock on Earth and also makes up a large portion of the oceanic crust. It is also found on the Moon and Mars.
Field identification & locations
Commonly found as rounded pebbles on beaches or riverbeds where basalt formations are eroding. Identified by its dark color, fine grain, and lack of visible large crystals.
