Atlasovite is an extremely rare copper-iron-bismuth oxychloride mineral discovered in the volcanic fumaroles of the Tolbachik volcano in Russia. It typically appears as dark, metallic-looking platy or tabular crystals formed by gas sublimation. Collectors prize it for its unique chemistry and extreme locality specificity.

Hardness

2-2.5

Mohs

Luster

Vitreous

Streak

Pale brown

Transparency

Transparent

mineralrareAtlasovite Group family

Atlasovite

Hardness: 2-2.5
Luster: Vitreous
Streak: Pale brown
Transparency: Transparent

No image

Is this atlasovite?

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 atlasovite with a known reference. Atlasovite sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: pale brown.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: dark brown.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: platy crystals, tabular aggregates.

Often confused with

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

How to tell apart: Streak differs, so Atlasovite leaves pale brown, Nabokoite leaves yellow-brown.

How to tell apart: Streak differs, so Atlasovite leaves pale brown, Ponomarevite leaves red-orange.

Compare →

Often found alongside atlasovite

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

All properties

Chemical formula: Cu₆FeBiO₄(SO₄)₅·KCl
Mohs hardness: 2-2.5
Density: 4.20 g/cm³
Colors: Dark brown
Streak: Pale brown
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Platy crystals, tabular aggregates
Cleavage: On {001}, perfect
Rarity: Rare
Uses: Collector
Host rock: As a volcanic sublimate

Where rockhounds find atlasovite

Classic worldwide localities

Tolbachik fissure volcano, Kamchatka Peninsula, Russia

Field-hunting tip

Where it forms: As a volcanic sublimate. If you start seeing nabokoite, anglesite, dolerophanite in float, you are in the right ground. Typical habit: platy crystals, tabular aggregates. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify atlasovite?+

Mohs hardness is 2-2.5. Luster: vitreous. The streak is pale brown. Common colors include dark brown.

Where is atlasovite found?+

Notable localities include Tolbachik fissure volcano, Kamchatka Peninsula, Russia.

Is atlasovite safe to handle?+

Atlasovite contains copper. Contains copper, iron, bismuth, and chlorine; avoid ingestion or inhalation of dust. Wear gloves and wash hands after handling.

What rocks look like atlasovite?+

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

What minerals are found with atlasovite?+

Atlasovite commonly co-occurs with Nabokoite, Anglesite, Dolerophanite, Euchlorine, Chloroxiphite, Atacamite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does atlasovite form in?+

Where it forms: As a volcanic sublimate. Working float back to the host body is the standard way to chase a fresh occurrence.

What is atlasovite used for?+

Atlasovite is used in collector.

Find atlasovite on the map

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