Plagionite is a rare lead-antimony sulfosalt known for its distinct thick, tabular, pseudo-hexagonal crystals. It is typically found in low-temperature hydrothermal veins and is highly prized by collectors of rare sulfide minerals for its metallic luster and complex crystal geometry.
Is this plagionite?
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 plagionite with a known reference. Plagionite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: blackish lead-gray, deep red-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: black, gray black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: botryoidal, massive, tabular.
Often confused with
Plagionite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Plagionite leaves blackish lead-gray, deep red-brown, Jamesonite leaves black. grayish.
How to tell apart: Streak differs, so Plagionite leaves blackish lead-gray, deep red-brown, Boulangerite leaves brownish.
How to tell apart: Streak differs, so Plagionite leaves blackish lead-gray, deep red-brown, Fülöppite leaves reddish gray.
Often found alongside plagionite
Minerals reported to co-occur with plagionite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₅Sb₈S₁₇
- Mohs hardness
- 2.5
- Density
- 5.54 g/cm³
- Colors
- BlackGray black
- Streak
- Blackish lead-gray, deep red-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Botryoidal, massive, tabular
- Cleavage
- Very good on {112}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In hydrothermal vein deposits
Where rockhounds find plagionite
Classic worldwide localities
- Wolfsberg, in the Harz Mountains (type locality), and Arnsberg, North Rhine-Westphalia, Germany
- Leyraux, Cantal, France
- Chazelles, Haute-Loire, France
- Les Cougnasses and Riou Beyrou, Hautes-Alpes, France
- Bournac, Montagne Noire, Finistère, France
- Bound Cliff, St. Endellion, Cornwall, England
Field-hunting tip
Where it forms: In hydrothermal vein deposits. If you start seeing cassiterite, franckeite, andorite in float, you are in the right ground. Typical habit: botryoidal, massive, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
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Find plagionite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
