mineral

Tumbled dark stone, possibly river pebble or hematite

Uncertain; candidates include hematite (Fe₂O₃), basalt, or dark chert

AI-generated identification · may be incorrect

Smooth, rounded, opaque dark brown-gray surface with subdued vitreous-to-waxy luster; hardness is approximately 5–7 depending on composition. No visible crystals or cleavage; specific gravity cannot be determined visually.

Identified September 22, 2026More mineral →

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Physical properties

Formation & geological history

Likely naturally rounded by water and/or artificially tumbled and polished. If hematite, it formed through iron-oxide precipitation or alteration; if basalt or chert, it represents volcanic or siliceous sedimentary material, respectively.

Uses & applications

Small polished stones are used for collecting, crafts, worry stones, and decorative objects; hematite may be sold as an ornamental gemstone. Common specimens usually have modest value.

Geological facts

The photograph does not provide enough evidence for a definitive identification. A red-brown streak strongly supports hematite, while a pale gray streak and lower density may indicate basalt or chert.

Field identification & locations

Test streak on unglazed porcelain: hematite leaves a red-to-reddish-brown streak; basalt and chert generally leave a faint gray or white streak. Common in river gravels and tumbles; value is typically $1–$10, rising to about $20–$50 for attractive, verified hematite.