Cobaltkoritnigite is a rare cobalt-bearing arsenate mineral typically found as small, delicate, rose-pink bladed crystals or crusts. It is most frequently encountered in the oxidation zones of cobalt-rich hydrothermal veins where it forms in association with other secondary arsenates.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareKoritnigite Group family

Cobaltkoritnigite

Hardness: 2-3
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this cobaltkoritnigite?

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 cobaltkoritnigite with a known reference. Cobaltkoritnigite sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cobaltkoritnigite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Cobaltkoritnigite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: pink, pale pink, rose.
5
Look at form & habit
Crystal system: triclinic. Typical habit: bladed crystals, radial aggregates, crusts.

Often confused with

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

Often found alongside cobaltkoritnigite

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

All properties

Chemical formula: Co(AsO₃OH)·H₂O
Mohs hardness: 2-3
Density: 3.32 g/cm³
Colors: Pink Pale Pink Rose
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Bladed Crystals, Radial Aggregates, Crusts
Cleavage: Perfect On {010}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Cobalt-arsenic Hydrothermal Ore Deposits
Typical price: $50-300 per specimen

Where rockhounds find cobaltkoritnigite

Classic worldwide localities

Jáchymov, Czech Republic
Bou Azzer, Morocco

Field-hunting tip

Look in oxidized zones of cobalt-arsenic hydrothermal ore deposits country — that is the host setting where cobaltkoritnigite typically forms. If you start seeing arsenopyrite, cobaltite, erythrite in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cobaltkoritnigite?+

Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is white. Common colors include pink, pale pink, rose.

Where is cobaltkoritnigite found?+

Notable localities include Jáchymov, Czech Republic; Bou Azzer, Morocco.

How much is cobaltkoritnigite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is cobaltkoritnigite safe to handle?+

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

What rocks look like cobaltkoritnigite?+

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

What minerals are found with cobaltkoritnigite?+

Cobaltkoritnigite commonly co-occurs with Arsenopyrite, Cobaltite, Erythrite, Skutterudite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does cobaltkoritnigite form in?+

Cobaltkoritnigite typically forms in oxidized zones of cobalt-arsenic hydrothermal ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cobaltkoritnigite used for?+

Cobaltkoritnigite is used in collector.

Find cobaltkoritnigite on the map

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