Crednerite is a rare copper manganese oxide mineral typically found in oxidized zones of copper deposits. It often occurs as dark, metallic, platy or foliated aggregates and is best identified by its association with other manganese and copper minerals.

Hardness

4.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Crednerite

Hardness: 4.5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this crednerite?

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 crednerite with a known reference. Crednerite sits at Mohs 4.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Crednerite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Crednerite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: platy crystals, foliated to lamellar masses.

Often confused with

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

How to tell apart: Streak differs — Crednerite leaves black, Hausmannite leaves brownish-red; luster reads metallic on Crednerite and submetallic on Hausmannite.

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Often found alongside crednerite

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

All properties

Chemical formula: CuMnO₂
Mohs hardness: 4.5
Density: 5.03 g/cm³
Colors: Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Platy Crystals, Foliated to Lamellar Masses
Cleavage: Perfect in One Direction
Rarity: Rare
Uses: Collector
Host rock: Oxidized Hydrothermal Manganese-copper Deposits
Typical price: $20-150 for small specimens

Where rockhounds find crednerite

Classic worldwide localities

Friedrichroda, Thuringia, Germany
Bisbee, Arizona, USA
Kalahari Manganese Field, South Africa

Field-hunting tip

Look in oxidized hydrothermal manganese-copper deposits country — that is the host setting where crednerite typically forms. If you start seeing tenorite, hausmannite, pyrolusite in float, you are in the right ground. Field specimens usually show a platy crystals, foliated to lamellar masses habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify crednerite?+

Mohs hardness is 4.5. It typically shows a metallic luster. The streak is black. Common colors include black.

Where is crednerite found?+

Notable localities include Friedrichroda, Thuringia, Germany; Bisbee, Arizona, USA; Kalahari Manganese Field, South Africa.

How much is crednerite worth?+

Typical asking prices fall in the range of $20-150 for small specimens. Quality, size, and provenance can move individual specimens well outside that range.

Is crednerite safe to handle?+

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

What rocks look like crednerite?+

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

What minerals are found with crednerite?+

Crednerite commonly co-occurs with Tenorite, Hausmannite, Pyrolusite, Calcite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does crednerite form in?+

Crednerite typically forms in oxidized hydrothermal manganese-copper deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is crednerite used for?+

Crednerite is used in collector.

Find crednerite on the map

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