Wallisite is an extremely rare lead-thallium sulfosalt mineral found almost exclusively in the famous Lengenbach Quarry in Switzerland. It typically occurs as small, dark metallic crystals associated with other complex sulfosalts in dolomite. Due to its toxicity and extreme rarity, it is highly sought after by advanced systematic mineral collectors.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareSartorite Group family

Wallisite

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

No image

Is this wallisite?

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 wallisite with a known reference. Wallisite sits at Mohs 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. Wallisite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Wallisite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, striated.

Often confused with

Wallisite vs. its common look-alikes — and how to tell them apart in the field.

mineral

Sartorite

Mohs 3

How to tell apart: Streak differs — Wallisite leaves black, Sartorite leaves chocolate-brown.

How to tell apart: Streak differs — Wallisite leaves black, Dufrénoysite leaves reddish-brown.

Compare →

Often found alongside wallisite

Minerals reported to co-occur with wallisite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: PbTlCuAs₂S₅
Mohs hardness: 3.5
Density: 5.02 g/cm³
Colors: Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Triclinic
Crystal habit: Tabular Crystals, Striated
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Dolomitic Marble
Typical price: $200-2000 per specimen depending on size and quality

Where rockhounds find wallisite

Classic worldwide localities

Lengenbach Quarry, Binn Valley, Switzerland

Field-hunting tip

Look in dolomitic marble country — that is the host setting where wallisite typically forms. If you start seeing sartorite, realgar, pyrite in float, you are in the right ground. Field specimens usually show a tabular crystals, striated habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify wallisite?+

Mohs hardness is 3.5. It typically shows a metallic luster. The streak is black. Common colors include black.

Where is wallisite found?+

Notable localities include Lengenbach Quarry, Binn Valley, Switzerland.

How much is wallisite worth?+

Typical asking prices fall in the range of $200-2000 per specimen depending on size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is wallisite safe to handle?+

It contains toxic constituents. Contains thallium, copper, lead, and arsenic. Always wash hands thoroughly after handling and avoid inhaling any dust or powder. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like wallisite?+

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

What minerals are found with wallisite?+

Wallisite commonly co-occurs with Sartorite, Realgar, Pyrite, Galena, Baumhauerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does wallisite form in?+

Wallisite typically forms in dolomitic marble. Working float back to the host body is the standard way to chase a fresh occurrence.

What is wallisite used for?+

Wallisite is used in collector.

Find wallisite on the map

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