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.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Gray-black

Transparency

Opaque

mineraluncommonJamesonite family

Plumosite

Also: feather ore

Hardness: 2.5
Luster: Metallic
Streak: Gray-black
Transparency: Opaque

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Is this plumosite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch plumosite with a known reference. Plumosite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Plumosite leaves a gray-black streak.
3
Read the luster
Hold the specimen under a strong light. Plumosite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: lead-gray, black.
5
Look at form & habit
Crystal 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 gray-black, Boulangerite leaves brownish-gray.

How to tell apart: Streak differs, so Plumosite leaves gray-black, Stibnite leaves lead-gray.

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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: 2.5
Density: 5.5-5.9 g/cm³
Colors: Lead-gray Black
Streak: Gray-black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Acicular, Capillary, Fibrous Masses
Cleavage: Perfect
Rarity: Uncommon
Uses: Collector
Host rock: Hydrothermal Sulfide Veins
Typical price: $20-150 for mineral specimens

Where rockhounds find plumosite

Classic worldwide localities

Harz Mountains, Germany
Príbram, Czech Republic
Baia Mare, Romania
Cornwall, England

Field-hunting tip

Look in hydrothermal sulfide veins country, the host setting where plumosite typically forms. If you start seeing galena, sphalerite, pyrite in float, you are in the right ground. Field specimens usually show a acicular, capillary, fibrous masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify plumosite?+

Mohs hardness is 2.5. It typically shows a metallic luster. The streak is gray-black. Common colors include lead-gray, black.

Where is plumosite found?+

Notable localities include Harz Mountains, Germany; Príbram, Czech Republic; Baia Mare, Romania; Cornwall, England.

How much is plumosite worth?+

Typical asking prices fall in the range of $20-150 for mineral specimens. Quality, size, and provenance can move individual specimens well outside that range.

Is plumosite safe to handle?+

It contains toxic constituents. Contains lead and antimony; wash hands thoroughly after handling and avoid inhaling dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like plumosite?+

Plumosite is most often confused with Jamesonite, Boulangerite, Stibnite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with plumosite?+

Plumosite commonly co-occurs with Galena, Sphalerite, Pyrite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does plumosite form in?+

Plumosite typically forms in hydrothermal sulfide veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is plumosite used for?+

Plumosite is used in collector.

Find plumosite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.