igneous
Dark mafic rock, possibly basalt or scoria
Basaltic rock; likely plagioclase–pyroxene ± olivine, with possible vesicular texture
AI-generated identification · may be incorrectDark gray to black, fine-grained and rough, with dull to weakly vitreous luster; typical hardness is about 5–6 Mohs, with no obvious cleavage. The image is low-resolution, so mineral identification and whether it is vesicular cannot be confirmed.
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Physical properties
Dark gray to black, fine-grained and rough, with dull to weakly vitreous luster; typical hardness is about 5–6 Mohs, with no obvious cleavage. The image is low-resolution, so mineral identification and whether it is vesicular cannot be confirmed.
Formation & geological history
Likely formed from rapidly cooled basaltic lava, commonly in volcanic flows or cinder deposits; age could range from recent to billions of years depending on locality.
Uses & applications
Basalt is widely used as crushed aggregate, roadstone, concrete material, and occasionally ornamental stone; scoria is also used for landscaping and lightweight construction fill.
Geological facts
Basalt is the most abundant volcanic rock on Earth and forms much of the oceanic crust. Vesicular basalt or scoria contains gas-bubble cavities produced during eruption.
Field identification & locations
Look for a very dark fine-grained matrix, heavy feel, possible tiny pale plagioclase crystals, and vesicles; a streak test is usually gray and a magnet may respond weakly if iron-bearing. Common worldwide in volcanic regions.
