Westerveldite is a rare nickel-iron arsenide mineral typically found as metallic, massive, or granular aggregates. It is primarily identified through laboratory analysis and is most commonly associated with other nickel-bearing ore minerals in ultramafic intrusive complexes.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Westerveldite

Hardness: >5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this westerveldite?

5-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 westerveldite with a known reference. Westerveldite sits at Mohs >5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: brownish white, gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: irregular grains, microscopic crystals.

Often confused with

Westerveldite vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside westerveldite

Minerals reported to co-occur with westerveldite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: FeAs
Mohs hardness: >5
Density: 8.13 g/cm³
Colors: Brownish white Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Irregular grains, microscopic crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: As minute inclusions in maucherite which occurs in chromite-nickeline ores

Where rockhounds find westerveldite

Classic worldwide localities

La Gallega mine, 3 km west of Ojén, Málaga Province, Spain
Ilímaussaq intrusion, southern Greenland
Seinäjoki, Finland
Birchtree mine, near Thompson, Manitoba, Canada

Field-hunting tip

Where it forms: As minute inclusions in maucherite which occurs in chromite-nickeline ores. If you start seeing maucherite, nickeline, cobaltite in float, you are in the right ground. Typical habit: irregular grains, microscopic crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify westerveldite?+

Mohs hardness is >5. Luster: metallic. The streak is black. Common colors include brownish white, gray.

Where is westerveldite found?+

Notable localities include La Gallega mine, 3 km west of Ojén, Málaga Province, Spain; Ilímaussaq intrusion, southern Greenland; Seinäjoki, Finland; Birchtree mine, near Thompson, Manitoba, Canada.

Is westerveldite safe to handle?+

Westerveldite contains arsenic and calls for real care. Contains arsenic. Handle with caution, wash hands after touching, and do not inhale dust.

What rocks look like westerveldite?+

Westerveldite is most often confused with Arsenopyrite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with westerveldite?+

Westerveldite commonly co-occurs with Maucherite, Nickeline, Cobaltite, Nickeloan löllingite, Fe–Co-rich gersdorffite, Rammelsbergite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does westerveldite form in?+

Where it forms: As minute inclusions in maucherite which occurs in chromite-nickeline ores. Working float back to the host body is the standard way to chase a fresh occurrence.

What is westerveldite used for?+

Westerveldite is used in collector.

Find westerveldite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.