Obradovicite-NaCu is an extremely rare arsenate-molybdate mineral typically found as a secondary mineral in oxidized hydrothermal deposits. Collectors usually find it as delicate yellow crystalline crusts or aggregates, primarily associated with major copper mining districts.
Is this obradovicite-nacu?
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 obradovicite-nacu with a known reference. Obradovicite-NaCu sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Obradovicite-NaCu leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Obradovicite-NaCu typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, greenish-yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts.
Often confused with
Obradovicite-NaCu vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside obradovicite-nacu
Minerals reported to co-occur with obradovicite-nacu. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCuFe₂(AsO₄)₂Mo(OH)₆·2H₂O
- Mohs hardness
- 2-3
- Density
- 3.32 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Hydrothermal Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find obradovicite-nacu
Classic worldwide localities
- Chuquicamata Mine, Chile
- Jachymov, Czech Republic
Field-hunting tip
Look in oxidized zones of hydrothermal ore deposits country — that is the host setting where obradovicite-nacu typically forms. If you start seeing jarosite, goethite, gypsum in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.





