Adolfpateraite is a very rare uranyl sulfate mineral originally discovered in the historic silver-mining district of Jáchymov. Collectors will typically find it as small, vibrant yellow crystals associated with other uranium-bearing minerals in hydrothermal vein deposits.

Hardness

Mohs

Luster

Vitreous

Streak

Pale yellow

Transparency

Transparent to translucent

mineralrare

Adolfpateraite

Hardness: ~2
Luster: Vitreous
Streak: Pale yellow
Transparency: Transparent to translucent

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Is this adolfpateraite?

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 adolfpateraite with a known reference. Adolfpateraite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: pale yellow.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: sulfur-yellow, greenish yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular to prismatic crystals.

Often confused with

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

Often found alongside adolfpateraite

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

All properties

Chemical formula: K(UO₂)(SO₄)(OH)·H₂O
Mohs hardness: ~2
Density: 4.24 g/cm³
Colors: Sulfur-yellowGreenish yellow
Streak: Pale yellow
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Tabular to prismatic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: A secondary mineral in the oxidized zone of a uranium deposit

Where rockhounds find adolfpateraite

Classic worldwide localities

Geschieber vein, fifth level of the Svornost (Einigkeit) shaft, Jáchymov (Sankt Joachimsthal) ore district, western Bohemia, Czech Republic

Field-hunting tip

Where it forms: A secondary mineral in the oxidized zone of a uranium deposit. If you start seeing gypsum, schoepite, čejkaite in float, you are in the right ground. Typical habit: tabular to prismatic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify adolfpateraite?+

Mohs hardness is ~2. Luster: vitreous. The streak is pale yellow. Common colors include sulfur-yellow, greenish yellow.

Where is adolfpateraite found?+

Notable localities include Geschieber vein, fifth level of the Svornost (Einigkeit) shaft, Jáchymov (Sankt Joachimsthal) ore district, western Bohemia, Czech Republic.

Is adolfpateraite safe to handle?+

Adolfpateraite contains uranium or thorium and calls for real care. Contains uranium and is radioactive. Handle with gloves, avoid inhalation of dust, and store in a sealed container away from living areas.

What rocks look like adolfpateraite?+

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

What minerals are found with adolfpateraite?+

Adolfpateraite commonly co-occurs with Gypsum, Schoepite, Čejkaite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does adolfpateraite form in?+

Where it forms: A secondary mineral in the oxidized zone of a uranium deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is adolfpateraite used for?+

Adolfpateraite is used in collector.

Find adolfpateraite on the map

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