igneous
Dark, coarse-grained rock (likely basalt)
Possibly basalt, composed chiefly of plagioclase and pyroxene; the image is not clear enough for a confident identification.
AI-generated identification · may be incorrectDark gray to black, rough and granular with scattered light-colored grains. Hardness and crystal structure cannot be determined from the image; basalt typically has Mohs hardness around 6 and a fine-grained groundmass.
Identified More igneous →
Explore Dark, coarse-grained rock (likely basalt) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark gray to black, rough and granular with scattered light-colored grains. Hardness and crystal structure cannot be determined from the image; basalt typically has Mohs hardness around 6 and a fine-grained groundmass.
Formation & geological history
If basalt, it formed when mafic lava cooled at or near the surface; its age and specific geological setting cannot be established from the image.
Uses & applications
Basalt is widely used as crushed aggregate, road stone, and building stone; this specimen has no evident jewelry use.
Geological facts
Basalt is one of Earth’s most common volcanic rocks and also forms much of the ocean floor.
Field identification & locations
The dark color and pale mineral flecks are consistent with basalt, but the image’s scale and detail are insufficient to distinguish it from other dark rocks. Field identification can be improved by checking grain size, density, and whether it reacts to a magnet; basalt occurs in volcanic regions worldwide.
