Fülöppite is a rare sulfosalt mineral recognized for its distinctive metallic luster and often sharp, tabular crystal form. It is most frequently found in hydrothermal vein deposits, particularly famous in the epithermal mines of Romania. Collectors prize well-defined specimens from the Herja mine, which are typically associated with other lead-antimony sulfides.
Is this fülöppite?
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 fülöppite with a known reference. Fülöppite 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: reddish gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: gray, bronze yellow, steel blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic.
Often confused with
Fülöppite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Fülöppite leaves reddish gray, Plagionite leaves blackish lead-gray, deep red-brown.
How to tell apart: Streak differs, so Fülöppite leaves reddish gray, Semseyite leaves black.
How to tell apart: Streak differs, so Fülöppite leaves reddish gray, Jamesonite leaves black. grayish.
Often found alongside fülöppite
Minerals reported to co-occur with fülöppite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₃Sb₈S₁₅
- Mohs hardness
- 2.5
- Density
- 5.22 g/cm³
- Colors
- Streak
- Reddish gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic
- Cleavage
- Good on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Of hydrothermal origin
Where rockhounds find fülöppite
Classic worldwide localities
- Baia Mare (Nagybánya) district, from the Dealul Crucii (Kereszthegy) (type locality) and Herja mines, Romania
- Wet Swine Gill, Caldbeck Fells, Cumbria, England
- Auliac, Cantal, France
- North Altyntopkan Pb–Zn skarn deposit, northwestern Karamazar, Tajikistan
- Skalnoye Hg–Sb deposit, central Kazakhstan
- Lake George antimony deposit, 40 km west of Fredricton, New Brunswick, Canada
Field-hunting tip
Where it forms: Of hydrothermal origin. If you start seeing zinkenite, semseyite, fizélyite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fülöppite?+
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Is fülöppite safe to handle?+
What rocks look like fülöppite?+
What minerals are found with fülöppite?+
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Find fülöppite on the map
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