Jamesonite is a lead-iron-antimony sulfosalt that crystallizes as fine, hair-thin acicular needles, sometimes forming felted matted masses (“feather ore”). It is one of the few common sulfides that exhibits genuine fibrous habit.
Properties
- Formula: Pb4FeSb6S14
- Crystal system: Monoclinic
- Hardness: 2.5
- Color: Dark steel-gray to grayish-black
- Streak: Grayish-black
- Luster: Metallic
- Cleavage: Good across {001}
- Density: 5.5 – 6.0 g/cm³
Occurrence in China
Jamesonite is the signature collector species of the Yaogangxian mine, Hunan alongside bournonite, where lustrous black needle bundles up to 10 cm long are produced. Wuzhou (Guangxi) and various Yunnan Pb-Zn-Sb mines produce additional material. Cornwall (UK) and Bolivia also yield notable specimens.
Identification
Hair-fine acicular metallic needles + hexagonal cross-section + Pb-Sb mining association. Distinguish from boulangerite (similar habit but typically thicker and more lustrous) by chemistry — only chemical analysis is fully decisive.
Collector Notes
Yaogangxian “feather ore” jamesonite needles standing on quartz drusy or arsenopyrite are among the most dramatic Chinese sulfide specimens. Care: fragile.
Found at these Localities
- Dachang Tin-Polymetallic Field (大厂锡多金属矿田)
- Cornwall Mining District (康沃尔矿区)
- Wuzhou Mine (梧州矿)
- Yaogangxian Mine (瑶岗仙矿)
- Yunnan (云南)
- Guangxi (广西)
- Hunan (湖南)
