Jentschite is a very rare sulfosalt mineral found almost exclusively in the famous Lengenbach Quarry in Switzerland. It typically presents as small, metallic-gray crystals within dolomite cavities and is highly prized by collectors of rare thallium-bearing minerals.
Is this jentschite?
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 jentschite with a known reference. Jentschite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: dark red.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic to submetallic.
- 4Match the color rangeCompare against the expected color range: black, dark red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic to tabular crystals.
Often confused with
Jentschite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Jentschite leaves dark red, Sartorite leaves chocolate-brown.
How to tell apart: Streak differs, so Jentschite leaves dark red, Liveingite leaves chocolate-brown.
How to tell apart: Streak differs, so Jentschite leaves dark red, Baumhauerite leaves chocolate-brown.
Often found alongside jentschite
Minerals reported to co-occur with jentschite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- TlPbAs₂SbS₆
- Mohs hardness
- 2-2.5
- Density
- 5.24 g/cm³
- Streak
- Dark red
- Luster
- Metallic to submetallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic to tabular crystals
- Cleavage
- Perfect on {101}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare in a hydrothermal deposit in dolostone
Where rockhounds find jentschite
Classic worldwide localities
- Lengenbach quarry, Binntal, Valais, Switzerland (type locality)
Field-hunting tip
Where it forms: Very rare in a hydrothermal deposit in dolostone. If you start seeing realgar, orpiment, hutchinsonite in float, you are in the right ground. Typical habit: prismatic to tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify jentschite?+
Where is jentschite found?+
Is jentschite safe to handle?+
What rocks look like jentschite?+
What minerals are found with jentschite?+
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Find jentschite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
