Protasite is a rare barium-uranium mineral known primarily from the Shinkolobwe mine in the Congo. It typically forms thin, orange, tabular crystals and is a highly sought-after species for advanced radioactive mineral collectors.

Hardness

2.5

Mohs

Luster

Adamantine

Streak

Yellow-orange

Transparency

Transparent

mineralrare

Protasite

Hardness: 2.5
Luster: Adamantine
Streak: Yellow-orange
Transparency: Transparent

No image

Is this protasite?

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 protasite with a known reference. Protasite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Protasite leaves a yellow-orange streak.
3
Read the luster
Hold the specimen under a strong light. Protasite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: orange, reddish-orange.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals.

Often confused with

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

mineral

Becquerelite

Mohs 2.5

How to tell apart: Streak differs — Protasite leaves yellow-orange, Becquerelite leaves yellow.

How to tell apart: Streak differs — Protasite leaves yellow-orange, Fourmarierite leaves orange-yellow.

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Often found alongside protasite

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

All properties

Chemical formula: Ba₂U₆O₂₁(OH)₂·3H₂O
Mohs hardness: 2.5
Density: 5.7 g/cm³
Colors: Orange Reddish-orange
Streak: Yellow-orange
Luster: Adamantine
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Uranium-rich Hydrothermal Deposits
Typical price: $100-500+ for micro-mount specimens

Where rockhounds find protasite

Classic worldwide localities

Shinkolobwe Mine, Democratic Republic of the Congo

Field-hunting tip

Look in uranium-rich hydrothermal deposits country — that is the host setting where protasite typically forms. If you start seeing curite, becquerelite, soddyite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify protasite?+

Mohs hardness is 2.5. It typically shows a adamantine luster. The streak is yellow-orange. Common colors include orange, reddish-orange.

Where is protasite found?+

Notable localities include Shinkolobwe Mine, Democratic Republic of the Congo.

How much is protasite worth?+

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

Is protasite safe to handle?+

This mineral is radioactive. It contains toxic constituents. Protasite is both radioactive and contains barium and uranium. Handle with extreme caution using gloves, store in lead-shielded containers, and avoid inhalation of dust or ingestion. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like protasite?+

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

What minerals are found with protasite?+

Protasite commonly co-occurs with Curite, Becquerelite, Soddyite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does protasite form in?+

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

What is protasite used for?+

Protasite is used in collector.

Find protasite on the map

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