mineral

Black tumbled stone, possibly obsidian

Undetermined; appearance may resemble obsidian (volcanic glass, SiO₂-rich)

AI-generated identification · may be incorrect

Small, smooth, glossy black pebble with no visible crystals. If obsidian, hardness is about 5–5.5 Mohs; the photo alone cannot confirm its identity or composition.

Identified September 26, 2026More mineral →

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Physical properties

Small, smooth, glossy black pebble with no visible crystals. If obsidian, hardness is about 5–5.5 Mohs; the photo alone cannot confirm its identity or composition.

Formation & geological history

Could be a naturally occurring stone shaped by tumbling or a manufactured polished specimen. Obsidian forms when silica-rich lava cools rapidly; its age and source cannot be determined from the image.

Uses & applications

Tumbled stones are used for collecting, decoration, and jewelry. Value depends on the actual material, size, and finish.

Geological facts

A glossy black appearance is not diagnostic: obsidian, black agate, and other stones can look similar when polished.

Field identification & locations

Identify by checking for glassy conchoidal fracture, translucency at thin edges, and hardness, ideally with expert testing. No locality can be inferred from the photograph.