mineral

Likely dark rounded stone or mineral fragment

Indeterminate; possibly a water-worn mafic rock such as basalt

AI-generated identification · may be incorrect

The image shows a smooth, dark gray, rounded object beneath cloudy water or glass. Apparent luster is wet/subvitreous; hardness, cleavage, crystal structure, and specific gravity cannot be determined visually.

Identified August 18, 2026More mineral →

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Physical properties

Formation & geological history

If basalt, it formed when mafic lava cooled rapidly, commonly in volcanic or oceanic settings, usually during the Cenozoic or older. The rounded shape likely reflects stream, beach, or sediment abrasion.

Uses & applications

Common basalt is used for aggregate, road stone, ballast, and landscaping; attractive polished pieces may be collected, but this specimen has no reliable gem value from the image alone.

Geological facts

The surrounding pale material and branching lines may be sediment, plant roots, or reflections rather than part of the specimen. Water strongly enhances the apparent darkness and gloss.

Field identification & locations

Test the dry surface: basalt is typically fine-grained, dense, dark gray to black, and may attract little or no magnetism; a streak test, fresh break, and magnification would improve identification. Common worldwide, especially volcanic regions.