Bradaczekite is a rare copper sodium arsenate mineral discovered in the volcanic fumaroles of the Tolbachik volcano. It typically occurs as delicate, bright blue to greenish-blue tabular crystals or thin crusts in high-temperature volcanic environments.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrare

Bradaczekite

Hardness: 3
Luster: Vitreous
Streak: White
Transparency: Translucent

No image

Is this bradaczekite?

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 bradaczekite with a known reference. Bradaczekite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Bradaczekite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Bradaczekite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, greenish-blue.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, crusts, aggregates.

Often confused with

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

mineral

Lammerite

Mohs 3.5

How to tell apart: Streak differs, so Bradaczekite leaves white, Lammerite leaves light green.

Compare →

Often found alongside bradaczekite

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

All properties

Chemical formula: NaCu₄(AsO₄)₃
Mohs hardness: 3
Density: 4.26 g/cm³
Colors: Blue Greenish-blue
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Crusts, Aggregates
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Fumarole Deposits
Typical price: $100-500 for small specimens

Where rockhounds find bradaczekite

Classic worldwide localities

Tolbachik volcano, Kamchatka, Russia

Field-hunting tip

Look in fumarole deposits country, the host setting where bradaczekite typically forms. If you start seeing lammerite, tenorite, hematite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify bradaczekite?+

Mohs hardness is 3. It typically shows a vitreous luster. The streak is white. Common colors include blue, greenish-blue.

Where is bradaczekite found?+

Notable localities include Tolbachik volcano, Kamchatka, Russia.

How much is bradaczekite worth?+

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

Is bradaczekite safe to handle?+

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

What rocks look like bradaczekite?+

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

What minerals are found with bradaczekite?+

Bradaczekite commonly co-occurs with Lammerite, Tenorite, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does bradaczekite form in?+

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

What is bradaczekite used for?+

Bradaczekite is used in collector.

Find bradaczekite on the map

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