Kudriavite is an extremely rare cadmium-lead bismuth sulfide mineral found in volcanic fumaroles. It typically forms as small, yellowish, metallic platy crystals occurring within the mineralized vents of high-temperature volcanoes.

Hardness

Mohs

Luster

Metallic

Streak

Yellow

Transparency

Opaque

mineralrare

Kudriavite

Hardness: 2
Luster: Metallic
Streak: Yellow
Transparency: Opaque

Is this kudriavite?

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 kudriavite with a known reference. Kudriavite 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. Kudriavite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Kudriavite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: yellow, pale yellow.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: platy crystals.

Often confused with

Kudriavite 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 Kudriavite leaves yellow, Galena leaves lead-gray.

How to tell apart: Streak differs, so Kudriavite leaves yellow, Bismuthinite leaves lead-gray.

Compare →

Often found alongside kudriavite

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

All properties

Chemical formula: (Cd,Pb)Bi₂S₄
Mohs hardness: 2
Density: 4.96 g/cm³
Colors: Yellow Pale Yellow
Streak: Yellow
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Platy Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Fumarole Deposits

Where rockhounds find kudriavite

Classic worldwide localities

Kudriavy volcano, Iturup Island, Kuril Islands, Russia

Field-hunting tip

Look in fumarole deposits country, the host setting where kudriavite typically forms. If you start seeing greenockite, wurtzite, sulfur in float, you are in the right ground. Field specimens usually show a platy crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kudriavite?+

Mohs hardness is 2. It typically shows a metallic luster. The streak is yellow. Common colors include yellow, pale yellow.

Where is kudriavite found?+

Notable localities include Kudriavy volcano, Iturup Island, Kuril Islands, Russia.

Is kudriavite safe to handle?+

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

What rocks look like kudriavite?+

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

What minerals are found with kudriavite?+

Kudriavite commonly co-occurs with Greenockite, Wurtzite, Sulfur. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kudriavite form in?+

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

What is kudriavite used for?+

Kudriavite is used in collector.

Find kudriavite on the map

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