igneous
Porphyritic Basalt
Extrusive igneous rock primarily composed of plagioclase and pyroxene
AI-generated identification · may be incorrectHardness of 6 on the Mohs scale, dark green to grey color with distinct white or light-colored plagioclase phenocrysts, and an aphanitic to fine-grained groundmass.
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Physical properties
Hardness of 6 on the Mohs scale, dark green to grey color with distinct white or light-colored plagioclase phenocrysts, and an aphanitic to fine-grained groundmass.
Formation & geological history
Formed from rapid cooling of mafic lava flows at or near the Earth's surface, consistent with volcanic activity found in the East African Rift region.
Uses & applications
Used primarily as crushed stone for construction, road aggregate, and dimension stone.
Geological facts
Porphyritic texture indicates a two-stage cooling history where larger crystals formed slowly underground before the magma erupted and cooled rapidly.
Field identification & locations
Easily identified by its contrasting light phenocrysts embedded in a dark volcanic matrix; common in volcanic regions worldwide.
