mineral

Small dark rock fragment

Uncertain; possibly weathered basalt or slag

AI-generated identification · may be incorrect

Gray-black, fine-grained to irregular, with a dull-to-submetallic luster; hardness and specific gravity cannot be determined reliably from the image. No visible crystals or cleavage are apparent.

Identified August 18, 2026More mineral →

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Physical properties

Gray-black, fine-grained to irregular, with a dull-to-submetallic luster; hardness and specific gravity cannot be determined reliably from the image. No visible crystals or cleavage are apparent.

Formation & geological history

If basalt, it formed from rapidly cooled mafic lava, commonly during relatively young volcanic activity; if slag, it is human-made and not geological. The photograph is insufficient to establish age or origin.

Uses & applications

A natural basalt fragment has uses in aggregate, roadstone, and construction; an isolated piece this small has essentially no commercial value. Slag may be industrial waste or an ornamental curiosity.

Geological facts

The specimen is only a few millimeters across and appears slightly porous or rough, which can occur in basalt, weathered rock, or industrial slag. A fresh surface, magnet test, and close inspection are needed for identification.

Field identification & locations

Check for vesicles, a uniform fine-grained texture, and weak magnetism to support basalt; glassy bubbles, metallic beads, or strongly magnetic behavior suggest slag. Common basalt sources include volcanic regions worldwide.