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.

Hardness

3-3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareSartorite Group family

Jentschite

Hardness: 3-3.5
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this jentschite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch jentschite with a known reference. Jentschite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Jentschite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Jentschite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: lead-gray, black.
5
Look at form & habit
Crystal 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.

mineral

Sartorite

Mohs 3

How to tell apart: Streak differs, so Jentschite leaves black, Sartorite 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: 3-3.5
Density: 5.59 g/cm³
Colors: Lead-gray Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Prismatic to Tabular Crystals
Cleavage: Perfect On {010}
Rarity: Rare
Uses: Collector
Host rock: Dolostone
Typical price: $100-500 thumbnail

Where rockhounds find jentschite

Classic worldwide localities

Lengenbach Quarry, Binntal, Switzerland

Field-hunting tip

Look in dolostone country, the host setting where jentschite typically forms. If you start seeing realgar, orpiment, pyrite in float, you are in the right ground. Field specimens usually show a prismatic to tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify jentschite?+

Mohs hardness is 3-3.5. It typically shows a metallic luster. The streak is black. Common colors include lead-gray, black.

Where is jentschite found?+

Notable localities include Lengenbach Quarry, Binntal, Switzerland.

How much is jentschite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is jentschite safe to handle?+

It contains toxic constituents. Contains thallium, lead, arsenic, and antimony. Handle with care, wash hands thoroughly after contact, and avoid creating dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like jentschite?+

Jentschite is most often confused with Sartorite, Liveingite, Baumhauerite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with jentschite?+

Jentschite commonly co-occurs with Realgar, Orpiment, Pyrite, Dolomite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does jentschite form in?+

Jentschite typically forms in dolostone. Working float back to the host body is the standard way to chase a fresh occurrence.

What is jentschite used for?+

Jentschite is used in collector.

Find jentschite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.