Naldrettite is a very rare palladium antimonide discovered in the copper-nickel ores of the Sudbury Igneous Complex. It typically occurs as microscopic grains intergrown with other platinum-group minerals, making it a challenging find even for advanced collectors. It is named in honor of Anthony J. Naldrett, a prominent Canadian geologist specializing in magmatic sulfide deposits.
Is this naldrettite?
4-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 naldrettite with a known reference. Naldrettite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: metallic.
- 3Match the color rangeCompare against the expected color range: white, silver-white.
- 4Look at form & habitCrystal system: orthorhombic. Typical habit: anhedral grains.
Often confused with
Naldrettite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside naldrettite
Minerals reported to co-occur with naldrettite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pd₂Sb
- Mohs hardness
- 4-5
- Density
- 10.694 g/cm³
- Colors
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Anhedral grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In drill core through the contact zone between massive and disseminated sulfide mineralization hosted by amphibolite and serpentinite replacing pyroxenite and peridotite
Where rockhounds find naldrettite
Classic worldwide localities
- Mesamax Northwest deposit, Cape Smith Fold belt, Ungava region, Québec, Canada
Field-hunting tip
Where it forms: In drill core through the contact zone between massive and disseminated sulfide mineralization hosted by amphibolite and serpentinite replacing pyroxenite and peridotite. If you start seeing clinochlore monoclinic pyrrhotite, pentlandite, chalcopyrite in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.







