Arsenuranylite is a rare secondary uranium mineral that typically forms as bright yellow, platy, or micaceous aggregates within the oxidation zones of uranium-bearing hydrothermal veins. Due to its radioactive nature and potential for toxic arsenic exposure, it is intended strictly for professional or experienced collector display.

Hardness

2-3

Mohs

Luster

Pearly

Streak

Yellow

Transparency

Translucent

mineralrare

Arsenuranylite

Hardness: 2-3
Luster: Pearly
Streak: Yellow
Transparency: Translucent

Is this arsenuranylite?

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 arsenuranylite with a known reference. Arsenuranylite 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. Arsenuranylite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Arsenuranylite typically shows a pearly luster.
4
Match the color range
Compare against the expected color range: yellow, orange-yellow.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: platy crystals, crusts, radial aggregates.

Often confused with

Arsenuranylite 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 Arsenuranylite leaves yellow, Autunite leaves pale yellow.

How to tell apart: Luster reads pearly on Arsenuranylite and earthy on Phosphuranylite.

Compare →

Often found alongside arsenuranylite

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

All properties

Chemical formula: Ca(UO₂)₄(AsO₄)₂(OH)₄·10H₂O
Mohs hardness: 2-3
Density: 4.67 g/cm³
Colors: Yellow Orange-yellow
Streak: Yellow
Luster: Pearly
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Platy Crystals, Crusts, Radial Aggregates
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Uranium Deposits
Typical price: $50-300 per specimen depending on size and association

Where rockhounds find arsenuranylite

Classic worldwide localities

Shinkolobwe mine, DR Congo
Jáchymov, Czech Republic
Wheal Gorland, England

Field-hunting tip

Look in oxidized uranium deposits country, the host setting where arsenuranylite typically forms. If you start seeing uraninite, metazeunerite, billietite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify arsenuranylite?+

Mohs hardness is 2-3. It typically shows a pearly luster. The streak is yellow. Common colors include yellow, orange-yellow.

Where is arsenuranylite found?+

Notable localities include Shinkolobwe mine, DR Congo; Jáchymov, Czech Republic; Wheal Gorland, England.

How much is arsenuranylite worth?+

Typical asking prices fall in the range of $50-300 per specimen depending on size and association. Quality, size, and provenance can move individual specimens well outside that range.

Is arsenuranylite safe to handle?+

This mineral is radioactive. It contains toxic constituents. This mineral is radioactive and contains arsenic. Handle with care, wear gloves when touching, avoid inhalation of dust, and store away from living areas in a lead-lined or sealed container. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like arsenuranylite?+

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

What minerals are found with arsenuranylite?+

Arsenuranylite commonly co-occurs with Uraninite, Metazeunerite, Billietite, Cuprosklodowskite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does arsenuranylite form in?+

Arsenuranylite typically forms in oxidized uranium deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is arsenuranylite used for?+

Arsenuranylite is used in collector.

Find arsenuranylite on the map

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