Nickelhexahydrite is a rare secondary sulfate mineral typically found as efflorescences or crusts in the oxidation zones of nickel-rich sulfide deposits. It is highly soluble in water and must be stored in a dry environment to prevent dehydration into lower-hydrate phases or total dissolution.
Is this nickelhexahydrite?
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 nickelhexahydrite with a known reference. Nickelhexahydrite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: bluish green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crusts, efflorescences, granular, rarely prismatic crystals.
Often confused with
Nickelhexahydrite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Nickelhexahydrite and pearly to vitreous on Hexahydrite.
How to tell apart: Streak differs, so Nickelhexahydrite leaves white, Morenosite leaves pale green to white.
How to tell apart: Streak differs, so Nickelhexahydrite leaves white, Retgersite leaves pale green.
Often found alongside nickelhexahydrite
Minerals reported to co-occur with nickelhexahydrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NiSO₄·6H₂O
- Mohs hardness
- 2
- Density
- 2.036 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Crusts, efflorescences, granular, rarely prismatic crystals
- Cleavage
- On {010}, probable, perfect; on {100}, less perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Precipitated from mine waters in the bottom of an open-pit nickel mine, and on nickel-bearing gabbro-dolerite rocks in the oxidation zone (Noril’sk region, Russia)
Where rockhounds find nickelhexahydrite
Classic worldwide localities
- Severnaya mine, Noril’sk, western Siberia, and in the Izumrudnye Kopi emerald mines, Asbest district, Ural Mountains, Russia
- Lahnaslampi talc deposit, Finland
- Riffelalp and Pollux, near Zermatt, Valais, Switzerland
- Droskovac, near Vares, Bosnia-Herzegovina
- Jáchymov (Joachimsthal), Czech Republic
- Bauhaus mine, Richelsdorfer Mountains, Hesse, Germany
Field-hunting tip
Where it forms: Precipitated from mine waters in the bottom of an open-pit nickel mine, and on nickel-bearing gabbro-dolerite rocks in the oxidation zone (Noril’sk region, Russia). If you start seeing morenosite in float, you are in the right ground. Typical habit: crusts, efflorescences, granular, rarely prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nickelhexahydrite?+
Where is nickelhexahydrite found?+
Is nickelhexahydrite safe to handle?+
What rocks look like nickelhexahydrite?+
What minerals are found with nickelhexahydrite?+
What kind of rock does nickelhexahydrite form in?+
What is nickelhexahydrite used for?+
Find nickelhexahydrite on the map
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