Lautite is a rare copper arsenic sulfide mineral that typically occurs in low-temperature hydrothermal veins. It often forms steel-gray tabular crystals or metallic massive aggregates and is most recognized for its association with silver and other arsenic-bearing minerals.
Is this lautite?
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 lautite with a known reference. Lautite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Lautite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Lautite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: iron-black, lead-gray, steel-gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals, massive, granular.
Often confused with
Lautite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside lautite
Minerals reported to co-occur with lautite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuAsS
- Mohs hardness
- 3
- Density
- 5.9-6.0 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular Crystals, Massive, Granular
- Cleavage
- Distinct On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins
- Typical price
- $50-500 depending on specimen quality and size
Where rockhounds find lautite
Classic worldwide localities
- Lauta, Marienberg, Saxony, Germany
- Jáchymov, Czech Republic
- Bou Azzer, Morocco
Field-hunting tip
Look in hydrothermal veins country, the host setting where lautite typically forms. If you start seeing arsenopyrite, chalcopyrite, galena in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.





