Edenharterite is an extremely rare thallium-lead sulfosalt discovered in the famous Lengenbach locality of the Swiss Alps. It typically occurs as small, lead-gray prismatic crystals embedded within dolomite, often associated with other exotic sulfosalts.
Is this edenharterite?
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 edenharterite with a known reference. Edenharterite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Edenharterite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Edenharterite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: lead-gray, black.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic crystals.
Often confused with
Edenharterite vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Edenharterite is noticeably harder (Mohs 3.5 vs. 1.5-2).

How to tell apart: Edenharterite is noticeably harder (Mohs 3.5 vs. 1.5-2); streak differs, so Edenharterite leaves black, Smithite leaves orange-red; luster reads metallic on Edenharterite and adamantine on Smithite.

How to tell apart: Edenharterite is noticeably harder (Mohs 3.5 vs. 2.5); streak differs, so Edenharterite leaves black, Galena leaves lead-gray.
Often found alongside edenharterite
Minerals reported to co-occur with edenharterite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Tl,Pb)₃As₅S₉
- Mohs hardness
- 3.5
- Density
- 4.87 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Dolomite Rocks
- Typical price
- $100-500+ for micro-mounts
Where rockhounds find edenharterite
Classic worldwide localities
- Lengenbach Quarry, Binn Valley, Switzerland
Field-hunting tip
Look in dolomite rocks country, the host setting where edenharterite typically forms. If you start seeing lengenbachite, smithite, realgar in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.


