Kapellasite is a rare copper zinc chloride mineral primarily found as small, vibrant green platy crystals in oxidized zones of ore deposits. It is highly sought after by collectors of micro-minerals due to its sharp, distinct habit often associated with other secondary copper species in the famous slags of Laurion.
Is this kapellasite?
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 kapellasite with a known reference. Kapellasite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light green-blue.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: bluish green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: encrustations.
Often confused with
Kapellasite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Kapellasite leaves light green-blue, Atacamite leaves apple-green.
How to tell apart: Kapellasite is noticeably harder (Mohs 4 vs. 3); streak differs, so Kapellasite leaves light green-blue, Paratacamite leaves green; luster reads adamantine on Kapellasite and vitreous on Paratacamite.
How to tell apart: Kapellasite is noticeably harder (Mohs 4 vs. 3); luster reads adamantine on Kapellasite and vitreous on Botallackite.
Often found alongside kapellasite
Minerals reported to co-occur with kapellasite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃Zn(OH)₆Cl₂
- Mohs hardness
- 4
- Density
- 3.55 g/cm³
- Colors
- Streak
- Light green-blue
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Encrustations
- Cleavage
- Good on {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- From weathering copper and zinc minerals in the presence of chloride ions
Where rockhounds find kapellasite
Classic worldwide localities
- Sounion No. 19 mine, Kamariza, Lavrion, Greece (type locality)
- Weathered slag of the Juliushütte, near Goslar, Harz mountains, Germany
Field-hunting tip
Where it forms: From weathering copper and zinc minerals in the presence of chloride ions. If you start seeing gypsum, paratacamite, atacamite in float, you are in the right ground. Typical habit: encrustations. Train your eye for that shape before scanning the outcrop.
Common questions
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Find kapellasite on the map
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