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, so Mutnovskite leaves grey, Galena leaves lead-gray.

How to tell apart: Streak differs, so 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, 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.