Tillmannsite is a very rare mercury-silver telluride mineral typically found as microscopic grains within hydrothermal ore deposits. It is best identified through laboratory analysis of metallic phases in polished sections, as it rarely forms distinct macroscopic crystals.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareTetrahedrite Group family

Tillmannsite

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

No image

Is this tillmannsite?

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 tillmannsite with a known reference. Tillmannsite 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. Tillmannsite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Tillmannsite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: silver-white, light gray.
5
Look at form & habit
Crystal system: cubic. Typical habit: anhedral grains.

Often confused with

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

Often found alongside tillmannsite

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

All properties

Chemical formula: Ag₃HgTe₄
Mohs hardness: 3.5
Density: 8.55 g/cm³
Colors: Silver-white Light Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Anhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find tillmannsite

Classic worldwide localities

Tillmanns, Siegerland, Germany
Hope's Nose, Torquay, England

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where tillmannsite typically forms. If you start seeing quartz, galena, pyrite in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tillmannsite?+

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

Where is tillmannsite found?+

Notable localities include Tillmanns, Siegerland, Germany; Hope's Nose, Torquay, England.

How much is tillmannsite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is tillmannsite safe to handle?+

It contains toxic constituents. Contains mercury and tellurium; handle with care and avoid inhalation of dust or ingestion. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like tillmannsite?+

Tillmannsite is most often confused with Tetrahedrite, Goldfieldite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with tillmannsite?+

Tillmannsite commonly co-occurs with Quartz, Galena, Pyrite, Siderite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tillmannsite form in?+

Tillmannsite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tillmannsite used for?+

Tillmannsite is used in collector.

Find tillmannsite on the map

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