Medenbachite is a rare secondary mineral found in the oxidation zones of arsenic-rich hydrothermal ore deposits. It typically forms small, distinct tabular crystals with a characteristic orange to reddish-orange color and adamantine luster.

Hardness

Mohs

Luster

Adamantine

Streak

Yellow

Transparency

Translucent

mineralrare

Medenbachite

Hardness: 4
Luster: Adamantine
Streak: Yellow
Transparency: Translucent

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Is this medenbachite?

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 medenbachite with a known reference. Medenbachite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Medenbachite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Medenbachite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: orange, reddish-orange, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Mixite

Mohs 3-4

How to tell apart: Streak differs — Medenbachite leaves yellow, Mixite leaves white; luster reads adamantine on Medenbachite and vitreous on Mixite.

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Often found alongside medenbachite

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

All properties

Chemical formula: Bi₂Fe(Cu,Fe)(OH)₂(AsO₄)₂
Mohs hardness: 4
Density: 5.65 g/cm³
Colors: Orange Reddish-orange Brown
Streak: Yellow
Luster: Adamantine
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $100-500 thumbnail

Where rockhounds find medenbachite

Classic worldwide localities

Grube Clara, Germany
Wittichen, Germany

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where medenbachite typically forms. If you start seeing quartz, baryte, mixite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify medenbachite?+

Mohs hardness is 4. It typically shows a adamantine luster. The streak is yellow. Common colors include orange, reddish-orange, brown.

Where is medenbachite found?+

Notable localities include Grube Clara, Germany; Wittichen, Germany.

How much is medenbachite worth?+

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

Is medenbachite safe to handle?+

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

What rocks look like medenbachite?+

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

What minerals are found with medenbachite?+

Medenbachite commonly co-occurs with Quartz, Baryte, Mixite, Pharmacosiderite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does medenbachite form in?+

Medenbachite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is medenbachite used for?+

Medenbachite is used in collector.

Find medenbachite on the map

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