Cobaltkieserite is a rare hydrated cobalt sulfate typically found as an alteration product in cobalt-rich ore deposits. Collectors should look for its distinct pink color in massive or granular forms, often associated with other secondary cobalt minerals.

Hardness

3.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareKieserite Group family

Cobaltkieserite

Hardness: 3.5
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this cobaltkieserite?

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 cobaltkieserite with a known reference. Cobaltkieserite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Cobaltkieserite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Cobaltkieserite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: pink, reddish-pink.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: granular to massive.

Often confused with

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

How to tell apart: Cobaltkieserite is noticeably harder (Mohs 3.5 vs. 2.5).

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Often found alongside cobaltkieserite

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

All properties

Chemical formula: CoSO₄·H₂O
Mohs hardness: 3.5
Density: 2.81 g/cm³
Colors: Pink Reddish-pink
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Granular to Massive
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Cobalt-rich Deposits
Typical price: $50-300 per specimen

Where rockhounds find cobaltkieserite

Classic worldwide localities

Laurion, Greece
Schneeberg, Germany
Bou Azzer, Morocco

Field-hunting tip

Look in oxidized hydrothermal cobalt-rich deposits country — that is the host setting where cobaltkieserite typically forms. If you start seeing cobaltite, erythrite, gypsum in float, you are in the right ground. Field specimens usually show a granular to massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cobaltkieserite?+

Mohs hardness is 3.5. It typically shows a vitreous luster. The streak is white. Common colors include pink, reddish-pink.

Where is cobaltkieserite found?+

Notable localities include Laurion, Greece; Schneeberg, Germany; Bou Azzer, Morocco.

How much is cobaltkieserite 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 cobaltkieserite safe to handle?+

It contains toxic constituents. Contains cobalt; avoid ingestion, inhalation of dust, or skin contact. Wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like cobaltkieserite?+

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

What minerals are found with cobaltkieserite?+

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

What kind of rock does cobaltkieserite form in?+

Cobaltkieserite typically forms in oxidized hydrothermal cobalt-rich deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cobaltkieserite used for?+

Cobaltkieserite is used in collector.

Find cobaltkieserite on the map

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