Atheneite is a very rare palladium arsenide mineral typically found as microscopic grains within platinum-group element deposits. It is best identified through microscopic examination and chemical analysis due to its extremely small, unassuming appearance in polished sections.

Hardness

3.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Atheneite

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

Is this atheneite?

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 atheneite with a known reference. Atheneite 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. Atheneite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Atheneite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: white, pale yellow.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: anhedral grains and inclusions.

Often confused with

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

mineral

Potarite

Mohs 3.5-4

How to tell apart: Streak differs — Atheneite leaves black, Potarite leaves silver-white.

How to tell apart: Palladium is the harder of the two (Mohs 4.75-5 vs. 3.5); streak differs — Atheneite leaves black, Palladium leaves silver-white.

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Often found alongside atheneite

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

All properties

Chemical formula: (Pd,Hg)₃As
Mohs hardness: 3.5
Density: 10.0-10.4 g/cm³
Colors: White Pale Yellow
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Hexagonal
Crystal habit: Anhedral Grains and Inclusions
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins in Platinum Group Element Deposits
Typical price: $100-500+ for micro-specimens

Where rockhounds find atheneite

Classic worldwide localities

Itabira, Brazil
Stillwater complex, Montana, USA

Field-hunting tip

Look in hydrothermal veins in platinum group element deposits country — that is the host setting where atheneite typically forms. If you start seeing potarite, palladium, gold in float, you are in the right ground. Field specimens usually show a anhedral grains and inclusions habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify atheneite?+

Mohs hardness is 3.5. It typically shows a metallic luster. The streak is black. Common colors include white, pale yellow.

Where is atheneite found?+

Notable localities include Itabira, Brazil; Stillwater complex, Montana, USA.

How much is atheneite worth?+

Typical asking prices fall in the range of $100-500+ for micro-specimens. Quality, size, and provenance can move individual specimens well outside that range.

Is atheneite safe to handle?+

It contains toxic constituents. Contains arsenic and mercury; avoid inhalation of dust and handle with caution to prevent ingestion. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like atheneite?+

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

What minerals are found with atheneite?+

Atheneite commonly co-occurs with Potarite, Palladium, Gold, Hematite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does atheneite form in?+

Atheneite typically forms in hydrothermal veins in platinum group element deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is atheneite used for?+

Atheneite is used in collector.

Find atheneite on the map

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