Mutnovskite is a rare lead arsenic sulfotelluride mineral discovered in the fumaroles of the Mutnovsky volcano. It is typically found as small, metallic-looking grains or intergrowths within volcanic sublimates, making it a highly prized specimen for advanced mineral collectors.

Hardness

1.5-2

Mohs

Luster

Metallic

Streak

Grey

Transparency

Opaque

mineralrare

Mutnovskite

Hardness: 1.5-2
Luster: Metallic
Streak: Grey
Transparency: Opaque

No image

Is this mutnovskite?

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 mutnovskite with a known reference. Mutnovskite sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Mutnovskite leaves a grey streak.
3
Read the luster
Hold the specimen under a strong light. Mutnovskite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: gray, white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: granular to massive.

Often confused with

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

mineral

Galena

Mohs 2.5

How to tell apart: Streak differs — Mutnovskite leaves grey, Galena leaves lead-gray.

How to tell apart: Streak differs — Mutnovskite leaves grey, Tetradymite leaves lead-gray.

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Often found alongside mutnovskite

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

All properties

Chemical formula: Pb₂AsS₂Te
Mohs hardness: 1.5-2
Density: 6.6-6.7 g/cm³
Colors: Gray White
Streak: Grey
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Granular to Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Fumarolic Deposits
Typical price: $100-500+ per specimen

Where rockhounds find mutnovskite

Classic worldwide localities

Mutnovsky Volcano, Kamchatka, Russia

Field-hunting tip

Look in fumarolic deposits country — that is the host setting where mutnovskite typically forms. If you start seeing galena, gold, tellurium in float, you are in the right ground. Field specimens usually show a granular to massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mutnovskite?+

Mohs hardness is 1.5-2. It typically shows a metallic luster. The streak is grey. Common colors include gray, white.

Where is mutnovskite found?+

Notable localities include Mutnovsky Volcano, Kamchatka, Russia.

How much is mutnovskite worth?+

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

Is mutnovskite safe to handle?+

It contains toxic constituents. Contains lead and arsenic; avoid inhalation of dust or ingestion and wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like mutnovskite?+

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

What minerals are found with mutnovskite?+

Mutnovskite commonly co-occurs with Galena, Gold, Tellurium, Realgar. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mutnovskite form in?+

Mutnovskite typically forms in fumarolic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mutnovskite used for?+

Mutnovskite is used in collector.

Find mutnovskite on the map

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