Parnauite is a rare secondary copper arsenate-sulfate mineral that forms distinctive acicular to bladed crystal sprays. Collectors typically find it as vibrant blue to greenish-blue crusts or small radial clusters within the oxidized zones of copper-rich hydrothermal ore deposits.
Is this parnauite?
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 parnauite with a known reference. Parnauite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: greenish white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: blue green, green, light blue.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: encrustations, rosette, scaly.
Often confused with
Parnauite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Parnauite leaves greenish white, Clinoclase leaves bluish green.
How to tell apart: Cornubite is the harder of the two (Mohs ~4 vs. ~2); streak differs, so Parnauite leaves greenish white, Cornubite leaves pale green.
How to tell apart: Streak differs, so Parnauite leaves greenish white, Lavendulan leaves light blue.
Often found alongside parnauite
Minerals reported to co-occur with parnauite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₉(AsO₄)₂SO₄(OH)₁₀·7H₂O
- Mohs hardness
- ~2
- Density
- 3.09 g/cm³
- Streak
- Greenish white
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Encrustations, rosette, scaly
- Cleavage
- Good
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- A rare secondary mineral in the oxidized zone of a hydrothermal Cu–Sn orebody in rhyolite porphyries and breccias (Majuba Hill, Nevada, USA)
Where rockhounds find parnauite
Classic worldwide localities
- Majuba Hill mine, Antelope district, Pershing Co., and the Burrus mine, Pyramid district, Washoe Co., Nevada, USA
- Grandview Mine, Grand Canyon, Coconino Co., and the Harquehala mine, Yuma Co., Arizona, USA
- Tucker’s tunnel uranium deposit, near Durango, Hinsdale Co., Colorado, USA
- Gold Hill, Tooele Co., Utah, USA
- Cap Garonne mine, near le Pradet, Var, France
- Neubulach, Wittichen, and in the Clara mine, near Oberwolfach, Black Forest, Germany
Field-hunting tip
Where it forms: A rare secondary mineral in the oxidized zone of a hydrothermal Cu–Sn orebody in rhyolite porphyries and breccias (Majuba Hill, Nevada, USA). If you start seeing spangolite, chalcophyllite, chenevixite in float, you are in the right ground. Typical habit: encrustations, rosette, scaly. Train your eye for that shape before scanning the outcrop.
Common questions
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Find parnauite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
