Bismuthinite
Chemical compound
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Bismuthinite is a mineral consisting of bismuth sulfide. It is an important ore for bismuth. The crystals are steel-grey to off-white with a metallic luster. It is soft enough to be scratched with a fingernail and rather dense.
Bismuthinite forms... Wikipedia
Color: Lead-gray to tin-white, with a yellowish or iridescent tarnish
Crystal class: Dipyramidal (mmm); H-M symbol: (2/m 2/m 2/m)
Crystal habit: Slender prismatic to acicular, massive lamellar
Crystal system: Orthorhombic
Formula (repeating unit): Bi2S3
Fracture: Uneven
Optical properties: Opaque