mineral

Bismuth crystal

Bismuth (Bi), commonly laboratory-grown hopper crystal

AI-generated identification · may be incorrect

Metallic silver-gray with iridescent oxide colors; Mohs hardness 2–2.5, relatively brittle, specific gravity about 9.8, and a rhombohedral crystal structure. The stepped, skeletal hopper form and rainbow tarnish are characteristic.

Identified August 18, 2026More mineral →

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Physical properties

Formation & geological history

Usually a human-grown geological specimen produced by melting purified bismuth and allowing it to cool slowly; natural bismuth crystals form in hydrothermal veins associated with tin, tungsten, and lead ores. Common localities include Bolivia, China, Germany, and Canada.

Uses & applications

Collected for its striking geometric form and iridescence; bismuth is used in low-melting alloys, medicines, pigments, and lead-free manufacturing, but this crystal is primarily decorative.

Geological facts

The colors come from a thin interference-producing oxide film, not intrinsic crystal color. Bismuth expands slightly on solidifying and is the most diamagnetic naturally occurring metal.

Field identification & locations

Identify by its heavy feel, brittle metallic surface, stair-step hopper geometry, and iridescent oxidation; it is not magnetically attracted. Avoid harsh abrasion, acids, and prolonged heating.