Mertieite is a rare palladium-antimony mineral typically found as microscopic grains in ultramafic rocks or concentrated in placer deposits. It is a metallic mineral that is highly dense and usually identified through microprobe analysis due to its scarcity and lack of distinct crystal form.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Mertieite

Hardness: 3.5
Luster: Metallic
Streak: Black
Transparency: Opaque

No image

Is this mertieite?

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 mertieite with a known reference. Mertieite sits at Mohs 3.5, 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: white, pale yellow.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: granular, irregular grains, intergrowths.

Often confused with

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

How to tell apart: Isomertieite is the harder of the two (Mohs 5.5 vs. 3.5).

Compare →

Often found alongside mertieite

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

All properties

Chemical formula: Pd₈Sb₂.₅As₀.₅
Mohs hardness: 3.5
Density: 9.9-10.2 g/cm³
Colors: White Pale yellow
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Granular, irregular grains, intergrowths
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: ultramafic rocks, placer deposits

Where rockhounds find mertieite

Classic worldwide localities

Goodnews Bay (Alaska, USA)
Stillwater Complex (Montana, USA)
Norilsk (Russia)

Field-hunting tip

Where it forms: ultramafic rocks, placer deposits. If you start seeing platinum group minerals, magnetite, chromite in float, you are in the right ground. Typical habit: granular, irregular grains, intergrowths. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify mertieite?+

Mohs hardness is 3.5. Luster: metallic. The streak is black. Common colors include white, pale yellow.

Where is mertieite found?+

Notable localities include Goodnews Bay (Alaska, USA); Stillwater Complex (Montana, USA); Norilsk (Russia).

Is mertieite safe to handle?+

Mertieite contains antimony and arsenic and calls for real care. Contains palladium and antimony, which can be toxic if ingested or inhaled as dust; handle with care and wash hands after handling.

What rocks look like mertieite?+

Mertieite is most often confused with Stibiopalladinite, Isomertieite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with mertieite?+

Mertieite commonly co-occurs with Platinum group minerals, Magnetite, Chromite, Chalcopyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does mertieite form in?+

Where it forms: ultramafic rocks, placer deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is mertieite used for?+

Mertieite is used in collector.

Find mertieite on the map

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