Běhounekite is a rare secondary uranyl sulfate mineral typically found as a result of the oxidation of uraninite. It manifests as delicate yellow crusts or small tabular crystals and is primarily known from the historic mining districts of the Czech Republic.

Hardness
2
Mohs
Luster
Vitreous
Streak
Pale Yellow
Transparency
Transparent

Is this běhounekite?

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 běhounekite with a known reference. Běhounekite 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. Běhounekite leaves a pale yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Běhounekite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellow, greenish-yellow.
  • 5
    Look at form & habit
    Crystal system: tetragonal. Typical habit: tabular crystals, crusts, pulverulent aggregates.

Often confused with

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

Often found alongside běhounekite

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

All properties

Chemical formula
UO₂(SO₄)·4H₂O
Mohs hardness
2
Density
3.5 g/cm³
Streak
Pale Yellow
Luster
Vitreous
Transparency
Transparent
Crystal system
Tetragonal
Crystal habit
Tabular Crystals, Crusts, Pulverulent Aggregates
Cleavage
None
Rarity
Rare
Uses
Collector
Host rock
Hydrothermal Uranium-bearing Veins
Typical price
$50-300 per specimen

Where rockhounds find běhounekite

Classic worldwide localities

  • Jáchymov, Czech Republic

Field-hunting tip

Look in hydrothermal uranium-bearing veins country — that is the host setting where běhounekite typically forms. If you start seeing johannite, jáchymovite, uranyl sulfates in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, pulverulent aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify běhounekite?+
Mohs hardness is 2. It typically shows a vitreous luster. The streak is pale yellow. Common colors include yellow, greenish-yellow.
Where is běhounekite found?+
Notable localities include Jáchymov, Czech Republic.
How much is běhounekite worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
Is běhounekite safe to handle?+
This mineral is radioactive. It contains toxic constituents. This mineral is radioactive and contains uranium; handle with gloves, avoid inhalation of dust, and store in a lead-lined container away from other mineral specimens and living spaces. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like běhounekite?+
Běhounekite is most often confused with Johannite, Zippeite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with běhounekite?+
Běhounekite commonly co-occurs with Johannite, Jáchymovite, Uranyl sulfates. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does běhounekite form in?+
Běhounekite typically forms in hydrothermal uranium-bearing veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is běhounekite used for?+
Běhounekite is used in collector.

Find běhounekite on the map

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