Plášilite is a rare secondary uranium mineral typically found as small, pale blue tabular crystals in oxidized hydrothermal veins. It is known primarily from the Jáchymov district in the Czech Republic and is highly sought after by collectors specializing in rare uranyl minerals.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Plášilite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this plášilite?

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 plášilite with a known reference. Plášilite 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. Plášilite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Plášilite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: blue, pale blue.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, crusts.

Often confused with

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

mineral

Liebigite

Mohs 2.5

How to tell apart: Streak differs — Plášilite leaves white, Liebigite leaves pale yellow.

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Often found alongside plášilite

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

Haynesite
mineral · Mohs 2-3

All properties

Chemical formula: Na(UO₂)(SeO₄)(OH)·2H₂O
Mohs hardness: 2
Density: 3.51 g/cm³
Colors: Blue Pale Blue
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Crusts
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Uranium-rich Vein Deposits
Typical price: $100-500 thumbnail size

Where rockhounds find plášilite

Classic worldwide localities

Jachymov, Czech Republic

Field-hunting tip

Look in hydrothermal uranium-rich vein deposits country — that is the host setting where plášilite typically forms. If you start seeing haynesite, ferro-celadonite, uranyl sulfates in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify plášilite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include blue, pale blue.

Where is plášilite found?+

Notable localities include Jachymov, Czech Republic.

How much is plášilite worth?+

Typical asking prices fall in the range of $100-500 thumbnail size. Quality, size, and provenance can move individual specimens well outside that range.

Is plášilite safe to handle?+

This mineral is radioactive. It contains toxic constituents. Contains uranium and selenium; handle with care using gloves, avoid inhalation of dust, and store in a sealed container away from living areas. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like plášilite?+

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

What minerals are found with plášilite?+

Plášilite commonly co-occurs with Haynesite, Ferro-celadonite, Uranyl sulfates. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does plášilite form in?+

Plášilite typically forms in hydrothermal uranium-rich vein deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is plášilite used for?+

Plášilite is used in collector.

Find plášilite on the map

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