igneous
Rounded gray stone, likely a fine-grained volcanic rock
Possibly andesite or basalt; the image does not show enough detail for a definitive identification
AI-generated identification · may be incorrectGray, fine- to medium-grained, with many pale elongated flecks; likely feldspar crystals in a darker groundmass. Exact hardness, luster, and specific gravity cannot be determined from the photo.
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Physical properties
Gray, fine- to medium-grained, with many pale elongated flecks; likely feldspar crystals in a darker groundmass. Exact hardness, luster, and specific gravity cannot be determined from the photo.
Formation & geological history
If volcanic, formed when lava cooled at or near Earth’s surface; its age and source are unknown. The rounded shape suggests prolonged natural abrasion or tumbling.
Uses & applications
Common volcanic stones are used as aggregate, paving or landscaping stone, and sometimes as collectible specimens.
Geological facts
The pale flecks may be plagioclase crystals, a common component of basaltic and andesitic rocks.
Field identification & locations
A volcanic origin is suggested by the compact texture and visible crystals, but a fresh broken surface or mineral tests would help distinguish basalt, andesite, and other rocks. Volcanic rocks occur worldwide in regions of past or present volcanism.
