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

No image

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 — Plumosite leaves gray-black, Boulangerite leaves brownish-gray.

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

Compare →

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 — that is 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.