Auricupride is a rare copper-gold intermetallic mineral typically found as microscopic grains or small masses in ultramafic rocks. It is visually similar to native gold but often exhibits a slightly different, brassier yellow hue and significantly higher density fluctuations due to variable copper content.
Is this auricupride?
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 auricupride with a known reference. Auricupride sits at Mohs ~3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: highly metallic.
- 4Match the color rangeCompare against the expected color range: bronze, copper.
- 5Look at form & habitCrystal system: cubic. Typical habit: anhedral grains, ductile, platy.
Often confused with
Auricupride vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside auricupride
Minerals reported to co-occur with auricupride. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃Au
- Mohs hardness
- ~3.5
- Density
- 11.5 g/cm³
- Colors
- BronzeCopper
- Streak
- Yellow
- Luster
- Highly metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Anhedral grains, ductile, platy
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In serpentinites as the product of low-temperature ordering and unmixing of Au–Cu solid solution alloys (Karabash deposit, Russia); in reduction halos in Permian red beds (near Zurich, Switzerland)
Where rockhounds find auricupride
Classic worldwide localities
- Karabash gold deposit, Soimon Valley, Southern Ural Mountains (type locality) and at the Oktyabr mine, Talnakh area, Noril’sk region, western Siberia, Russia
- Laksia and Pefkos, Cyprus
- Found northwest of Zurich, Switzerland
- El Indio mine, El Indio-Tambo district, east of La Serena, Coquimbo, Chile
Field-hunting tip
Where it forms: In serpentinites as the product of low-temperature ordering and unmixing of Au–Cu solid solution alloys (Karabash deposit, Russia); in reduction halos in Permian red beds (near Zurich, Switzerland). If you start seeing gold, copper in float, you are in the right ground. Typical habit: anhedral grains, ductile, platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify auricupride?+
Where is auricupride found?+
Is auricupride safe to handle?+
What rocks look like auricupride?+
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Find auricupride on the map
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