Pentlandite is the primary source of nickel and typically occurs in granular or massive aggregates within sulfide ore bodies. It is easily recognized by its distinct bronze-yellow color and tendency to be found in close association with magnetic pyrrhotite. Collectors often prize specimens from the major nickel-copper mining districts like Sudbury.
Is this pentlandite?
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 pentlandite with a known reference. Pentlandite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Pentlandite leaves a light bronze-brown streak.
- 3Read the lusterHold the specimen under a strong light. Pentlandite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: bronze-yellow, brownish-yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: granular, massive, rarely as octahedral crystals.
Often confused with
Pentlandite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Pentlandite leaves light bronze-brown, Pyrrhotite leaves dark grey to black.
How to tell apart: Streak differs, so Pentlandite leaves light bronze-brown, Chalcopyrite leaves greenish-black.
How to tell apart: Pyrite is the harder of the two (Mohs 6-6.5 vs. 3.5-4); streak differs, so Pentlandite leaves light bronze-brown, Pyrite leaves greenish-black to brownish-black.
Often found alongside pentlandite
Minerals reported to co-occur with pentlandite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Ni)₉S₈
- Mohs hardness
- 3.5-4
- Density
- 4.6-5.0 g/cm³
- Streak
- Light Bronze-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Granular, Massive, Rarely as Octahedral Crystals
- Cleavage
- None
- Rarity
- Common
- Uses
- Industrial, Ore of Nickel, Collector
- Host rock
- Mafic and Ultramafic Igneous Rocks
- Typical price
- $10-60 for small mineral specimens
Where rockhounds find pentlandite
Classic worldwide localities
- Sudbury, Ontario, Canada
- Norilsk, Russia
- Bushveld Complex, South Africa
- Kambalda, Australia
- Voisey's Bay, Canada
Field-hunting tip
Look in mafic and ultramafic igneous rocks country, the host setting where pentlandite typically forms. If you start seeing pyrrhotite, chalcopyrite, magnetite in float, you are in the right ground. Field specimens usually show a granular, massive, rarely as octahedral crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find pentlandite on the map
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