Štěpite is a rare uranium arsenite. It was approved as a distinct mineral species in 2012, from material found in Czech Republic.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

Gray to greenish gray

Transparency

Transparent

mineralrarePhosphate Group family

Štěpite

Štěpite is a rare uranium arsenite. It was approved as a distinct mineral species in 2012, from material found in Czech Republic.

Hardness: 2-3
Luster: Vitreous
Streak: Gray to greenish gray
Transparency: Transparent

Is this štěpite?

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 štěpite with a known reference. Štěpite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: gray to greenish gray.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: emerald green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: tabular crystals, massive, crusts.

Often confused with

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

mineral

Autunite

Mohs 2-2.5

How to tell apart: Streak differs, so Štěpite leaves gray to greenish gray, Autunite leaves pale yellow.

How to tell apart: Streak differs, so Štěpite leaves gray to greenish gray, Torbernite leaves pale green.

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Often found alongside štěpite

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

All properties

Chemical formula: U(AsO₃OH)₂·4H₂O
Mohs hardness: 2-3
Density: 3.90 g/cm³
Colors: Emerald green
Streak: Gray to greenish gray
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Tabular crystals, massive, crusts
Cleavage: Perfect on {001}
Rarity: Rare
Uses: Collector
Host rock: A post-mining secondary mineral developed by weathering in a humid climate of a Ag-As-Bi-Co-Ni-U hydrothermal vein-type deposit

Where rockhounds find štěpite

Classic worldwide localities

Jáchymov, Czech Republic

Field-hunting tip

Where it forms: A post-mining secondary mineral developed by weathering in a humid climate of a Ag-As-Bi-Co-Ni-U hydrothermal vein-type deposit. If you start seeing native arsenic, arsenopyrite, pyrite in float, you are in the right ground. Typical habit: tabular crystals, massive, crusts. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify štěpite?+

Mohs hardness is 2-3. Luster: vitreous. The streak is gray to greenish gray. Common colors include emerald green.

Where is štěpite found?+

Notable localities include Jáchymov, Czech Republic.

Is štěpite safe to handle?+

Štěpite contains arsenic and uranium or thorium and calls for real care. Contains arsenic, which is toxic if ingested or inhaled as dust. Contains uranium and is radioactive; store it apart from other specimens. Wash hands thoroughly after handling and avoid creating dust.

What rocks look like štěpite?+

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

What minerals are found with štěpite?+

Štěpite commonly co-occurs with Native arsenic, Arsenopyrite, Pyrite, Arsenolite, Bĕhounekite, Claudetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does štěpite form in?+

Where it forms: A post-mining secondary mineral developed by weathering in a humid climate of a Ag-As-Bi-Co-Ni-U hydrothermal vein-type deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is štěpite used for?+

Štěpite is used in collector.

Find štěpite on the map

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