Jolliffeite is a rare nickel arsenic selenide belonging to the gersdorffite group. It is typically found as small, metallic grains within hydrothermal vein systems associated with uranium mineralization in the Athabasca Basin.
Is this jolliffeite?
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 jolliffeite with a known reference. Jolliffeite sits at Mohs >3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: tin white.
- 5Look at form & habitCrystal system: cubic. Typical habit: anhedral grains.
Often confused with
Jolliffeite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Gersdorffite is the harder of the two (Mohs 5.5 vs. >3); streak differs, so Jolliffeite leaves black, Gersdorffite leaves grayish black.
How to tell apart: Cobaltite is the harder of the two (Mohs 5.5 vs. >3); streak differs, so Jolliffeite leaves black, Cobaltite leaves grayish black.
Often found alongside jolliffeite
Minerals reported to co-occur with jolliffeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NiAsSe
- Mohs hardness
- >3
- Density
- 7.1 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Anhedral grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- From a drill core in a fracture zone near a dolomite–peridotite contact
Where rockhounds find jolliffeite
Classic worldwide localities
- Fish Hook Bay area, Shirley Peninsula, north shore of Lake Athabaska, 18 km south of Uranium City, Saskatchewan, Canada (type locality)
Field-hunting tip
Where it forms: From a drill core in a fracture zone near a dolomite–peridotite contact. If you start seeing clausthalite, pb–bi–ag selenides, gold in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify jolliffeite?+
Where is jolliffeite found?+
Is jolliffeite safe to handle?+
What rocks look like jolliffeite?+
What minerals are found with jolliffeite?+
What kind of rock does jolliffeite form in?+
What is jolliffeite used for?+
Find jolliffeite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
