Namuwite is a rare secondary zinc-copper sulfate mineral typically found as small, thin platy crystals or delicate crusts in oxidized zones of ore deposits. It is best identified by its distinct pale blue or greenish-blue color and perfect basal cleavage, often requiring magnification for accurate identification. Collectors primarily source it from classic oxidized base metal localities where it occurs alongside other zinc minerals.
Is this namuwite?
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 namuwite with a known reference. Namuwite 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: very pale green.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: light green, pale sea green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: encrustations, hexagonal, platy.
Often confused with
Namuwite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Namuwite leaves very pale green, Hydrozincite leaves white.
How to tell apart: Serpierite is the harder of the two (Mohs 3.5-4 vs. 2); streak differs, so Namuwite leaves very pale green, Serpierite leaves greenish white; luster reads pearly on Namuwite and vitreous, pearly on cleavages on Serpierite.
How to tell apart: Streak differs, so Namuwite leaves very pale green, Devilline leaves pale green; luster reads pearly on Namuwite and vitreous, may be pearly on {001} on Devilline.
Often found alongside namuwite
Minerals reported to co-occur with namuwite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Zn₄SO₄(OH)₆(H₂O)·3H₂O
- Mohs hardness
- 2
- Density
- 2.77 g/cm³
- Colors
- Light greenPale sea green
- Streak
- Very pale green
- Luster
- Pearly
- Transparency
- Semitransparent
- Crystal system
- Trigonal
- Crystal habit
- Encrustations, hexagonal, platy
- Cleavage
- Perfect on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An uncommon secondary mineral formed in the oxidized zone of hydrothermal Cu–Zn bearing mineral deposits; may be derived from metallic slags
Where rockhounds find namuwite
Classic worldwide localities
- ZCA#4 mine, Balmat, St. Lawrence Co., New York, USA
- Aberllyn lead mine, about two km from Bettws-y-coed, Llanrwst district, Gwynedd, and at the Frongoch mine, Dyfed, Wales
- Smallcleugh mine, Nenthead, Cumbria, and in the Waterbank mine, Ecton Hill, Staffordshire, England
- Harz Mountains, from Granetal, at the Glücksrad mine, near Oberschulenberg, and in slag at the Juliushütte, Astfeld, Germany
- Friedrichssegen mine, near Bad Ems, and at Virneberg, near Rheinbreitbach, Rhineland-Palatinate, Germany
- Stolberg, near Aachen, North Rhineland-Westphalia, Germany
Field-hunting tip
Where it forms: An uncommon secondary mineral formed in the oxidized zone of hydrothermal Cu–Zn bearing mineral deposits; may be derived from metallic slags. If you start seeing hydrozincite, schulenbergite, serpierite in float, you are in the right ground. Typical habit: encrustations, hexagonal, platy. Train your eye for that shape before scanning the outcrop.
Common questions
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Find namuwite on the map
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