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.

Hardness
4-5
Mohs
Luster
Metallic
Transparency
Opaque

Is this naldrettite?

4-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try to scratch naldrettite with a known reference. Naldrettite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
  • 2
    Read the luster
    Hold the specimen under a strong light. Luster: metallic.
  • 3
    Match the color range
    Compare against the expected color range: white, silver-white.
  • 4
    Look at form & habit
    Crystal 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
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.

Common questions

How do you identify naldrettite?+
Mohs hardness is 4-5. Luster: metallic. Common colors include white, silver-white.
Where is naldrettite found?+
Notable localities include Mesamax Northwest deposit, Cape Smith Fold belt, Ungava region, Québec, Canada.
Is naldrettite safe to handle?+
Naldrettite contains antimony. Wash your hands afterwards, never grind or breathe the dust, and store it apart from specimens you handle often.
What rocks look like naldrettite?+
Naldrettite is most often confused with Stibiopalladinite, Geversite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with naldrettite?+
Naldrettite commonly co-occurs with Clinochlore monoclinic pyrrhotite, Pentlandite, Chalcopyrite, Galena, Sphalerite, Cobaltite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does naldrettite form in?+
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. Working float back to the host body is the standard way to chase a fresh occurrence.
What is naldrettite used for?+
Naldrettite is used in collector.

Find naldrettite on the map

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