Shadlunite is a rare lead-bearing member of the pentlandite group typically found within copper-nickel sulfide ore bodies. It occurs as massive, brass-yellow to bronze aggregates that are nearly impossible to distinguish from similar sulfides without laboratory analysis like X-ray diffraction.
Is this shadlunite?
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 shadlunite with a known reference. Shadlunite sits at Mohs 4, 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: bronze.
- 5Look at form & habitCrystal system: cubic. Typical habit: microscopic crystals, twinning common.
Often confused with
Shadlunite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Shadlunite leaves black, Pentlandite leaves pale bronze-brown.
How to tell apart: Streak differs, so Shadlunite leaves black, Chalcopyrite leaves greenish black.
Often found alongside shadlunite
Minerals reported to co-occur with shadlunite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Pb,Cd)(Fe,Cu)₈S₈
- Mohs hardness
- 4
- Density
- 4.72 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Microscopic crystals, twinning common
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As tiny grains and veinlets cutting Cu–Ni sulfide ores
Where rockhounds find shadlunite
Classic worldwide localities
- Minnamax Cu–Ni sulfide deposit, Duluth Gabbro complex, near Hibbing, St. Louis Co., Minnesota, and from the Cove mine, McCoy district, Lander Co., Nevada, USA
- Majak (type locality) and Oktyabr mines, Talnakh area, Noril’sk region, western Siberia, and at the Ust’-Khann’ya intrusive, lower Khann’ya River, Vilyui River basin, eastern Siberia, Russia
Field-hunting tip
Where it forms: As tiny grains and veinlets cutting Cu–Ni sulfide ores. If you start seeing manganese-shadlunite, cubanite, talnakhite in float, you are in the right ground. Typical habit: microscopic crystals, twinning common. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify shadlunite?+
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What rocks look like shadlunite?+
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Find shadlunite on the map
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