Plumosite is a fibrous, hair-like variety of jamesonite known for its distinctive 'feather ore' appearance. It typically occurs as delicate, bundled needle-like crystals in low-to-medium temperature hydrothermal lead-antimony veins.
Is this plumosite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch plumosite with a known reference. Plumosite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: dark gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: lead gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, capillary, fibrous masses.
Often confused with
Plumosite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Plumosite leaves dark gray, Jamesonite leaves black. grayish.
How to tell apart: Streak differs, so Plumosite leaves dark gray, Boulangerite leaves brownish.
How to tell apart: Streak differs, so Plumosite leaves dark gray, Stibnite leaves lead-gray.
Often found alongside plumosite
Minerals reported to co-occur with plumosite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂Sb₂S₅
- Mohs hardness
- 2-3
- Density
- 5.5-5.9 g/cm³
- Colors
- Streak
- Dark gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, capillary, fibrous masses
- Cleavage
- Good
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- The mineral name is considered to be generic for feathery lead sulphosalts (eg. boulangerite)
Where rockhounds find plumosite
Classic worldwide localities
- Harz Mountains, Germany
- Príbram, Czech Republic
- Baia Mare, Romania
- Cornwall, England
Field-hunting tip
Where it forms: The mineral name is considered to be generic for feathery lead sulphosalts (eg. boulangerite). If you start seeing galena, sphalerite, pyrite in float, you are in the right ground. Typical habit: acicular, capillary, fibrous masses. Train your eye for that shape before scanning the outcrop.
More plumosite photos
Common questions
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Find plumosite on the map
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