Löllingite is an iron-arsenic mineral often appearing as silver-white to steel-gray prismatic crystals or dense granular masses. It is frequently associated with other arsenic minerals in high-temperature hydrothermal veins and is notoriously difficult to distinguish from arsenopyrite without analytical testing. Due to its arsenic content, collectors should always exercise proper hygiene after handling.
Is this löllingite?
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 löllingite with a known reference. Löllingite sits at Mohs 5-5.5, 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: silvery white, tarnish gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: massive, prismatic, twinning common.
Often confused with
Löllingite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Löllingite leaves grayish black, Arsenopyrite leaves black.
How to tell apart: Streak differs, so Löllingite leaves grayish black, Skutterudite leaves black.
Often found alongside löllingite
Minerals reported to co-occur with löllingite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- FeAs₂
- Mohs hardness
- 5-5.5
- Density
- 7.40 g/cm³
- Colors
- Silvery whiteTarnish gray
- Streak
- Grayish black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Massive, prismatic, twinning common
- Cleavage
- Rarely distinct on {010}, {101}
- Rarity
- Uncommon
- Uses
- Collector, Ore of arsenic
- Host rock
- In mesothermal deposits associated with other sulfides and with calcite gangue; also in pegmatites
Where rockhounds find löllingite
Classic worldwide localities
- Mt. Mica, near Paris, Oxford Co., Maine, USA
- Franklin and Sterling Hill, Ogdensburg, Sussex Co., New Jersey, USA
- Gersoll mine, near Keystone, Pennington Co., South Dakota, USA
- Lölling, near Hüttenberg, Carinthia (type locality), Austria
- Schladming, Styria, Austria
- Reichenstein, Silesia, Poland
Field-hunting tip
Where it forms: In mesothermal deposits associated with other sulfides and with calcite gangue; also in pegmatites. If you start seeing skutterudite, bismuth, nickeline in float, you are in the right ground. Typical habit: massive, prismatic, twinning common. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify löllingite?+
Where is löllingite found?+
Is löllingite safe to handle?+
What rocks look like löllingite?+
What minerals are found with löllingite?+
What kind of rock does löllingite form in?+
What is löllingite used for?+
Find löllingite on the map
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