igneous
Porphyritic Basalt
Extrusive Igneous Rock
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale. Dark gray to black groundmass with distinct lighter plagioclase or pyroxene phenocrysts. Aphanitic to porphyritic texture with dull luster.
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Physical properties
Hardness of 6 on the Mohs scale. Dark gray to black groundmass with distinct lighter plagioclase or pyroxene phenocrysts. Aphanitic to porphyritic texture with dull luster.
Formation & geological history
Formed from rapidly cooling mafic lava flows on the Earth's surface, often during volcanic eruptions.
Uses & applications
Used primarily in construction, as crushed aggregate for road building, and as dimension stone.
Geological facts
Porphyritic texture indicates a two-stage cooling history where magma partially cooled underground before erupting.
Field identification & locations
Identify by its dark, fine-grained matrix embedded with larger, contrasting mineral crystals. Found globally in volcanic regions.
