Gillardite is a rare copper-nickel hydroxychloride mineral that typically forms as delicate, bright green platy or micaceous aggregates. It is primarily identified by its characteristic vibrant green color and association with nickel ore deposits in oxidized zones. Due to its scarcity and fragile crystal habit, it is highly sought after by systematic mineral collectors.
Is this gillardite?
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 gillardite with a known reference. Gillardite 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. Gillardite leaves a light green streak.
- 3Read the lusterHold the specimen under a strong light. Gillardite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: green, bright green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, rosettes.
Often confused with
Gillardite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Atacamite is the harder of the two (Mohs 3-3.5 vs. 2); streak differs — Gillardite leaves light green, Atacamite leaves apple green; luster reads pearly on Gillardite and adamantine to vitreous on Atacamite.
How to tell apart: Paratacamite is the harder of the two (Mohs 3 vs. 2); streak differs — Gillardite leaves light green, Paratacamite leaves apple green; luster reads pearly on Gillardite and adamantine on Paratacamite.
How to tell apart: Clinoatacamite is the harder of the two (Mohs 3 vs. 2); streak differs — Gillardite leaves light green, Clinoatacamite leaves apple green; luster reads pearly on Gillardite and vitreous on Clinoatacamite.
Often found alongside gillardite
Minerals reported to co-occur with gillardite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃Ni(OH)₆Cl₂
- Mohs hardness
- 2
- Density
- 2.8 g/cm³
- Colors
- Streak
- Light Green
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy Crystals, Crusts, Rosettes
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Nickel Sulfide Deposits
- Typical price
- $50-300 per specimen depending on quality and size
Where rockhounds find gillardite
Classic worldwide localities
- Kambalda, Western Australia
Field-hunting tip
Look in oxidized nickel sulfide deposits country — that is the host setting where gillardite typically forms. If you start seeing millerite, goethite, magnesite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, rosettes habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find gillardite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
