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, so 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, 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.