igneous
Dark gray rounded rock, likely basalt
Basalt (tentative; visual identification only)
AI-generated identification · may be incorrectFine-grained, dark gray, dull surface with rounded, weathered contours; individual crystals are not visible. Basalt is typically Mohs 5–6, with a fine-grained interlocking crystal structure and no obvious cleavage; density is about 2.8–3.0 g/cm³.
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Physical properties
Fine-grained, dark gray, dull surface with rounded, weathered contours; individual crystals are not visible. Basalt is typically Mohs 5–6, with a fine-grained interlocking crystal structure and no obvious cleavage; density is about 2.8–3.0 g/cm³.
Formation & geological history
If basalt, it formed when iron- and magnesium-rich lava cooled rapidly at or near the surface. Its age and exact formation environment cannot be determined from the photograph.
Uses & applications
Basalt is widely used as crushed aggregate, road stone, and building material; attractive pieces may be kept as specimens.
Geological facts
The photo does not show diagnostic features such as visible minerals, vesicles, or a fresh fracture, so other dark, fine-grained rocks are possible.
Field identification & locations
Check a fresh break for a uniformly fine texture and test hardness; basalt should scratch glass. Basalt is plausible in Iran, but the coarse location alone cannot confirm it.
