Rhodarsenide is a rare rhodium arsenide mineral that occurs primarily as small, metallic grains within platinum-group mineral assemblages. It is most frequently found in alluvial deposits derived from ultramafic rocks or in chromitite layers. Collectors prize it as a micro-mineral due to its extreme scarcity and association with platinum-group elements.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Rhodarsenide

Hardness: 3
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this rhodarsenide?

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 rhodarsenide with a known reference. Rhodarsenide sits at Mohs 3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Rhodarsenide leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Rhodarsenide typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: white, silver-white.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: granular.

Often confused with

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

mineral

Sperrylite

Mohs 6-7

How to tell apart: Sperrylite is the harder of the two (Mohs 6-7 vs. 3).

Often found alongside rhodarsenide

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

All properties

Chemical formula: Rh₂As
Mohs hardness: 3
Density: 11.32 g/cm³
Colors: White Silver-white
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Granular
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Ultramafic Rocks

Where rockhounds find rhodarsenide

Classic worldwide localities

Kandagubai, India
Itabira, Brazil
Miass, Russia

Field-hunting tip

Look in ultramafic rocks country, the host setting where rhodarsenide typically forms. If you start seeing magnetite, chromite, gold in float, you are in the right ground. Field specimens usually show a granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rhodarsenide?+

Mohs hardness is 3. It typically shows a metallic luster. The streak is black. Common colors include white, silver-white.

Where is rhodarsenide found?+

Notable localities include Kandagubai, India; Itabira, Brazil; Miass, Russia.

Is rhodarsenide safe to handle?+

It contains toxic constituents. Contains arsenic, which is toxic; avoid inhaling dust or handling with bare hands without washing thoroughly. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like rhodarsenide?+

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

What minerals are found with rhodarsenide?+

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

What kind of rock does rhodarsenide form in?+

Rhodarsenide typically forms in ultramafic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is rhodarsenide used for?+

Rhodarsenide is used in collector.

Find rhodarsenide on the map

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