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. Streak: variable.
- 3Read the lusterHold the specimen under a strong light. Luster: variable.
- 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, gray, olive-green, shining; luster reads variable on Radioactive Mineral and submetallic to greasy, 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 vitreous, pearly on {001} 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, subadamantine, waxy, pearly on cleavages; becoming dull on dehydration to metatorbernite 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
Where it forms: granite pegmatites, hydrothermal veins, sedimentary uranium deposits. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Typical habit: variable. 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.







