Karpovite is a rare thallium vanadium sulfate that forms sheaf-like aggregates. It is a sublimate on rock around a volcanic fumarole. Associated minerals include shcherbinaite, pauflerite and bobjonesite. It was first described from First cinder cone, North Breach of the Great Fissure Tolbachik volcano, Kamchatka Peninsula, Russia.

Hardness

Mohs

Luster

Adamantine

Streak

White

Transparency

Transparent

mineralrare

Karpovite

Hardness: ~2
Luster: Adamantine
Streak: White
Transparency: Transparent

No image

Is this karpovite?

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 karpovite with a known reference. Karpovite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: adamantine.
4
Match the color range
Compare against the expected color range: white with a bluish tint.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: sheaf-like aggregates.

Often confused with

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

mineral

Kovdorskite

Mohs 4

How to tell apart: Kovdorskite is the harder of the two (Mohs 4 vs. ~2); luster reads adamantine on Karpovite and vitreous on Kovdorskite.

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Often found alongside karpovite

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

All properties

Chemical formula: Tl₂VO(SO₄)₂(H₂O)
Mohs hardness: ~2
Density: 4.743 g/cm³
Colors: White with a bluish tint
Streak: White
Luster: Adamantine
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Sheaf-like aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A sublimate on rock around a volcanic fumarole

Where rockhounds find karpovite

Classic worldwide localities

First cinder cone, North Breach of the Great Fissure Tolbachik volcano, Kamchatka Peninsula, Russia

Field-hunting tip

Where it forms: A sublimate on rock around a volcanic fumarole. If you start seeing shcherbinaite, pauflerite, bobjonesite in float, you are in the right ground. Typical habit: sheaf-like aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify karpovite?+

Mohs hardness is ~2. Luster: adamantine. The streak is white. Common colors include white with a bluish tint.

Where is karpovite found?+

Notable localities include First cinder cone, North Breach of the Great Fissure Tolbachik volcano, Kamchatka Peninsula, Russia.

Is karpovite safe to handle?+

Karpovite contains thallium and vanadium and calls for real care. Contains thallium, which is toxic if ingested or inhaled as dust. Wash hands thoroughly after handling and avoid creating dust.

What rocks look like karpovite?+

Karpovite is most often confused with Kovdorskite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with karpovite?+

Karpovite commonly co-occurs with Shcherbinaite, Pauflerite, Bobjonesite, Markhininite, Evdokimovite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does karpovite form in?+

Where it forms: A sublimate on rock around a volcanic fumarole. Working float back to the host body is the standard way to chase a fresh occurrence.

What is karpovite used for?+

Karpovite is used in collector.

Find karpovite on the map

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