Schlemaite is an extremely rare copper-lead selenide mineral named after its type locality in the Schlema-Hartenstein district. It is typically found as small, lead-gray metallic grains associated with other selenium-bearing minerals in hydrothermal uranium veins. Collectors generally prize it as a rare species of interest for advanced mineralogical suites.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Schlemaite

Hardness: 3
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this schlemaite?

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 schlemaite with a known reference. Schlemaite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: black, silvery gray.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: intergrown crystals.

Often confused with

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

mineral

Clausthalite

Mohs 2.5-3

How to tell apart: Streak differs, so Schlemaite leaves black, Clausthalite leaves grayish black.

How to tell apart: Streak differs, so Schlemaite leaves black, Berzelianite leaves shining.

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Often found alongside schlemaite

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

All properties

Chemical formula: (Cu,□)₆(Pb,Bi)Se₄
Mohs hardness: 3
Density: 7.54 g/cm³
Colors: Black Silvery gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Intergrown crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In vein-type uranium deposit

Where rockhounds find schlemaite

Classic worldwide localities

Niederschlema-Alberoda vein-type uranium depost at Hartensein, Erzgebirge, Germany (type locality)

Field-hunting tip

Where it forms: In vein-type uranium deposit. If you start seeing clausthalite, eucairite, löllingite in float, you are in the right ground. Typical habit: intergrown crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify schlemaite?+

Mohs hardness is 3. Luster: metallic. The streak is black. Common colors include black, silvery gray.

Where is schlemaite found?+

Notable localities include Niederschlema-Alberoda vein-type uranium depost at Hartensein, Erzgebirge, Germany (type locality).

Is schlemaite safe to handle?+

Schlemaite contains copper, lead and selenium. Contains selenium and lead; avoid inhalation of dust or ingestion, and wash hands thoroughly after handling.

What rocks look like schlemaite?+

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

What minerals are found with schlemaite?+

Schlemaite commonly co-occurs with Clausthalite, Eucairite, Löllingite, Berzelianite, Tiemannite, Umangite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does schlemaite form in?+

Where it forms: In vein-type uranium deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is schlemaite used for?+

Schlemaite is used in collector.

Find schlemaite on the map

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