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?
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 naldrettite with a known reference. Naldrettite sits at Mohs 4.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Naldrettite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Naldrettite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: white, silver-white.
- 5Look 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
- 9.64 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Magmatic Sulfide Deposits
- Typical price
- $100-500+ per microscopic specimen
Where rockhounds find naldrettite
Classic worldwide localities
- Sudbury District, Ontario, Canada
Field-hunting tip
Look in magmatic sulfide deposits country — that is the host setting where naldrettite typically forms. If you start seeing sperrylite, kotulskite, michenerite in float, you are in the right ground. Field specimens usually show a anhedral grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find naldrettite on the map
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