Rock Identifier
Bismuth crystal aggregate (Bismuth (Bi), commonly laboratory-grown) — mineral
mineral

Bismuth crystal aggregate

Bismuth (Bi), commonly laboratory-grown

AI-generated identification · may be incorrect

Metallic, iridescent pink-purple, blue, green, and gold surface from a thin oxide film; Mohs hardness 2–2.5, metallic luster, rhombohedral crystal structure, perfect cleavage, and specific gravity about 9.78. The stepped, hopper-like geometry is characteristic of crystallized bismuth.

Identified More mineral
Explore Bismuth crystal aggregate in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Metallic, iridescent pink-purple, blue, green, and gold surface from a thin oxide film; Mohs hardness 2–2.5, metallic luster, rhombohedral crystal structure, perfect cleavage, and specific gravity about 9.78. The stepped, hopper-like geometry is characteristic of crystallized bismuth.

Formation & geological history

Usually produced by melting and slowly cooling refined bismuth, rather than forming naturally; natural bismuth occurs in hydrothermal veins associated with tin, tungsten, lead, and silver deposits. Natural specimens are uncommon and may be Paleozoic to younger depending on the host deposit.

Uses & applications

Primarily a collector specimen, educational display, and decorative object; bismuth is also used in low-melting alloys, pharmaceuticals, pigments, and environmentally safer lead substitutes.

Geological facts

Its vivid colors are oxidation effects, not the intrinsic color of the metal. Bismuth is strongly diamagnetic and expands slightly when it solidifies.

Field identification & locations

Identify by the heavy weight, brittle metal, iridescent oxide coating, and hopper/rhombohedral stepped crystals; distinguish it from chalcopyrite by its much higher density and softer, more brittle character. Common sources include Bolivia, Peru, China, and laboratory sellers.