Leucopyrite, widely known by the name Löllingite, is an iron arsenide mineral characterized by its bright silver-white metallic appearance. It is frequently confused with arsenopyrite but can often be distinguished by its lack of sulfur content and specific associations in hydrothermal ore deposits.
Is this leucopyrite?
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 leucopyrite with a known reference. Leucopyrite sits at Mohs 5.5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: grayish-black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silver-white, steel-gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic crystals, massive, granular.
Often confused with
Leucopyrite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Leucopyrite leaves grayish-black, Arsenopyrite leaves black.
How to tell apart: Streak differs, so Leucopyrite leaves grayish-black, Safflorite leaves grayish black.
How to tell apart: Streak differs, so Leucopyrite leaves grayish-black, Skutterudite leaves black.
Often found alongside leucopyrite
Minerals reported to co-occur with leucopyrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- FeAs₂
- Mohs hardness
- 5.5-6
- Density
- 7.4-7.5 g/cm³
- Colors
- Streak
- Grayish-black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic crystals, massive, granular
- Cleavage
- Distinct on {010}
- Rarity
- Uncommon
- Uses
- Collector, Ore of arsenic
- Host rock
- hydrothermal veins, skarns, metamorphic rocks
Where rockhounds find leucopyrite
2 mapped spotsClassic worldwide localities
- Lölling, Austria
- Franklin, New Jersey, USA
- Cobalt, Ontario, Canada
- Gedrite, Norway
Field-hunting tip
Where it forms: hydrothermal veins, skarns, metamorphic rocks. If you start seeing arsenopyrite, siderite, calcite in float, you are in the right ground. Typical habit: prismatic crystals, massive, granular. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New York. Start trip planning there.
More leucopyrite photos
Common questions
How do you identify leucopyrite?+
Where is leucopyrite found?+
Can I find leucopyrite in the United States?+
Is leucopyrite safe to handle?+
What rocks look like leucopyrite?+
What minerals are found with leucopyrite?+
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Find leucopyrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
