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.

Hardness

2-3

Mohs

Luster

Vitreous

Streak

Very Pale Yellowish Green

Transparency

Transparent

mineralrareObradovicite Group family

Obradovicite-NaCu

Hardness: 2-3
Luster: Vitreous
Streak: Very Pale Yellowish Green
Transparency: Transparent

No image

Is this obradovicite-nacu?

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 obradovicite-nacu with a known reference. Obradovicite-NaCu sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Obradovicite-NaCu leaves a very pale yellowish green streak.
3
Read the luster
Hold the specimen under a strong light. Obradovicite-NaCu typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellowish green.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: platy crystals, crusts.

Often confused with

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

mineral

Molybdite

Mohs 3-4

How to tell apart: Streak differs, so Obradovicite-NaCu leaves very pale yellowish green, Molybdite leaves white; luster reads vitreous on Obradovicite-NaCu and adamantine on Molybdite.

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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: Yellowish Green
Streak: Very Pale Yellowish Green
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Platy Crystals, Crusts
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Hydrothermal Ore Deposits

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, 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.

Common questions

How do you identify obradovicite-nacu?+

Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is very pale yellowish green. Common colors include yellowish green.

Where is obradovicite-nacu found?+

Notable localities include Chuquicamata Mine, Chile; Jachymov, Czech Republic.

Is obradovicite-nacu safe to handle?+

It contains toxic constituents. Contains arsenic and copper; wash hands after handling and avoid inhaling dust or powder. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like obradovicite-nacu?+

Obradovicite-NaCu is most often confused with Molybdite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with obradovicite-nacu?+

Obradovicite-NaCu commonly co-occurs with Jarosite, Goethite, Gypsum, Molybdenite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does obradovicite-nacu form in?+

Obradovicite-NaCu typically forms in oxidized zones of hydrothermal ore deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is obradovicite-nacu used for?+

Obradovicite-NaCu is used in collector.

Find obradovicite-nacu on the map

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