A radioactive mineral is any species containing uranium or thorium, such as uraninite or autunite. Use a Geiger counter to identify a specimen, and follow strict storage protocols to minimize radiation exposure.
Is this radioactive mineral?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch radioactive mineral with a known reference. Radioactive Mineral sits at Mohs 1-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Radioactive Mineral leaves a variable streak.
- 3Read the lusterHold the specimen under a strong light. Radioactive Mineral typically shows a variable luster.
- 4Match the color rangeCompare against the expected color range: yellow, green, black, orange, brown.
- 5Look at form & habitCrystal system: variable. Typical habit: variable.
Often confused with
Radioactive Mineral vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Streak differs, so Radioactive Mineral leaves variable, Uraninite leaves brownish-black to greenish-black; luster reads variable on Radioactive Mineral and submetallic to dull on Uraninite.

How to tell apart: Streak differs, so Radioactive Mineral leaves variable, Autunite leaves pale yellow; luster reads variable on Radioactive Mineral and pearly on Autunite.

How to tell apart: Streak differs, so Radioactive Mineral leaves variable, Torbernite leaves pale green; luster reads variable on Radioactive Mineral and vitreous on Torbernite.
Often found alongside radioactive mineral
Minerals reported to co-occur with radioactive mineral. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 1-6
- Density
- 3.5-10.0 g/cm³
- Streak
- Variable
- Luster
- Variable
- Transparency
- Opaque
- Crystal system
- Variable
- Crystal habit
- Variable
- Cleavage
- Variable
- Fluorescence
- Often Fluorescent
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Granite Pegmatites, Hydrothermal Veins, Sedimentary Uranium Deposits
Where rockhounds find radioactive mineral
1 mapped spotsClassic worldwide localities
- Democratic Republic of the Congo
- Canada
- USA
- Czech Republic
- France
Field-hunting tip
Look in granite pegmatites, hydrothermal veins, sedimentary uranium deposits country, the host setting where radioactive mineral typically forms. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Field specimens usually show a variable habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New Mexico. Start trip planning there.




