Anduoite is a rare ruthenium arsenide mineral typically found as small grains within ultramafic rock environments. Collectors look for its distinct metallic luster and association with chromite and other platinum-group element bearing ores.
Is this anduoite?
5-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 anduoite with a known reference. Anduoite sits at Mohs 7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: grayish black.
- 3Read the lusterHold the specimen under a strong light. Luster: dull metallic.
- 4Match the color rangeCompare against the expected color range: lead gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: inclusions, microscopic crystals.
Often confused with
Anduoite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Anduoite is noticeably harder (Mohs 7 vs. 5-5.5); luster reads dull metallic on Anduoite and metallic on Löllingite.
How to tell apart: Anduoite is noticeably harder (Mohs 7 vs. 5.5-6); streak differs, so Anduoite leaves grayish black, Arsenopyrite leaves black; luster reads dull metallic on Anduoite and metallic on Arsenopyrite.
Often found alongside anduoite
Minerals reported to co-occur with anduoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- RuAs₂
- Mohs hardness
- 7
- Density
- 8.692 g/cm³
- Colors
- Streak
- Grayish black
- Luster
- Dull metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Inclusions, microscopic crystals
- Cleavage
- At least one noted
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Of magmatic origin, as very rare inclusions in chromian spinel in chromitite bodies enclosed variously by augite peridotite, serpentinized dunite, harzburgite, and pyroxenite
Where rockhounds find anduoite
Classic worldwide localities
- Anduo chromite deposit, northern Tibet, China
- Kapitanov chromite deposit, near Zvenyhorodka, Ukraine
- Maja e Sukës chromite deposit, Tropoja massif, Albania
Field-hunting tip
Where it forms: Of magmatic origin, as very rare inclusions in chromian spinel in chromitite bodies enclosed variously by augite peridotite, serpentinized dunite, harzburgite, and pyroxenite. If you start seeing chromian spinel, pyrite, pyrrhotite in float, you are in the right ground. Typical habit: inclusions, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify anduoite?+
Where is anduoite found?+
Is anduoite safe to handle?+
What rocks look like anduoite?+
What minerals are found with anduoite?+
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Find anduoite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
