Cervelleite is an extremely rare silver telluride sulfide typically found as tiny, microscopic inclusions within other silver minerals. It is primarily identified through laboratory analysis and is highly sought after by advanced mineral collectors for its chemical rarity.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Cervelleite

Hardness: 2.5
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this cervelleite?

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 cervelleite with a known reference. Cervelleite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cervelleite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Cervelleite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: gray, black.
5
Look at form & habit
Crystal system: cubic. Typical habit: anhedral grains.

Often confused with

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

How to tell apart: Streak differs — Cervelleite leaves black, Petzite leaves iron-black.

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Often found alongside cervelleite

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

All properties

Chemical formula: Ag₄TeS
Mohs hardness: 2.5
Density: 8.8-8.9 g/cm³
Colors: Gray Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Anhedral Grains
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Epithermal Gold-silver Veins
Typical price: $200-800+ for micro-specimens

Where rockhounds find cervelleite

Classic worldwide localities

Susuman district, Russia
Hokkaido, Japan

Field-hunting tip

Look in epithermal gold-silver veins country — that is the host setting where cervelleite typically forms. If you start seeing acanthite, hessite, gold 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 cervelleite?+

Mohs hardness is 2.5. It typically shows a metallic luster. The streak is black. Common colors include gray, black.

Where is cervelleite found?+

Notable localities include Susuman district, Russia; Hokkaido, Japan.

How much is cervelleite worth?+

Typical asking prices fall in the range of $200-800+ for micro-specimens. Quality, size, and provenance can move individual specimens well outside that range.

Is cervelleite safe to handle?+

It contains toxic constituents. Contains silver and tellurium; handle with care to avoid ingestion or inhalation of dust. Wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like cervelleite?+

Cervelleite is most often confused with Acanthite, Hessite, Petzite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with cervelleite?+

Cervelleite commonly co-occurs with Acanthite, Hessite, Gold, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does cervelleite form in?+

Cervelleite typically forms in epithermal gold-silver veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cervelleite used for?+

Cervelleite is used in collector.

Find cervelleite on the map

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