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.
Is this rhodarsenide?
4-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch rhodarsenide with a known reference. Rhodarsenide sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: metallic.
- 3Match the color rangeCompare against the expected color range: brown.
- 4Look at form & habitCrystal system: orthorhombic. Typical habit: inclusions.
Often confused with
Rhodarsenide vs. its common look-alikes, and how to tell them apart in the field.
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
- 4-5
- Density
- 11.27-11.32 g/cm³
- Colors
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Inclusions
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In fluvial placers in a river draining a chromitite-bearing ophiolite (TL)
Where rockhounds find rhodarsenide
Classic worldwide localities
- Srebrnica River, near Veluce, central Serbia (TL)
- Pustaya River placer, Kamchatka Peninsula, eastern Russia and Simonovsky Brook, tributary of the Malaya Krokhalevka River, Salair Range, Eastern Siberia, Russia
- Onverwacht pipe, eastern Bushveld Complex, South Africa (eluvial)
Field-hunting tip
Where it forms: In fluvial placers in a river draining a chromitite-bearing ophiolite (TL). If you start seeing pt-fe alloys, ru-os-ir alloys, hollingworthite in float, you are in the right ground. Typical habit: inclusions. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify rhodarsenide?+
Where is rhodarsenide found?+
Is rhodarsenide safe to handle?+
What rocks look like rhodarsenide?+
What minerals are found with rhodarsenide?+
What kind of rock does rhodarsenide form in?+
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Find rhodarsenide on the map
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