Bismuthinite is a bismuth sulfide and the principal ore of bismuth. Sharp metallic needle-clusters in green fluorite or smoky quartz cavities make Yaogangxian Mine in Hunan the worldwide reference locality. Pristine specimens look like bursts of gray steel inside transparent fluorite – one of Chinese mineralogy's most photogenic combinations.
Key Facts
- Mohs hardness 2 – very soft; can be scratched with a fingernail.
- Specific gravity 6.78 – heavy for a metallic sulfide.
- Frequently develops iridescent rainbow tarnish over months.
- Yaogangxian (Hunan) is the global reference for collector specimens.
- Native bismuth occasionally accompanies bismuthinite at the same locality.
The Chinese Angle
Yaogangxian Mine in Hunan is the world reference for bismuthinite specimens – sharp prismatic needles often 2-5 cm in radiating sprays inside green fluorite cubes or quartz vugs. Combination matrix specimens with fluorite, scheelite, wolframite, and arsenopyrite are characteristic of the deposit and command premium collector prices. Xianghualing produces a secondary supply.
Found at these Localities
- Xianghualing Mine (香花岭)
- Yaogangxian Mine (瑶岗仙矿)
- Hunan (湖南)
