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.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareHexahydrite Group family

Nickelhexahydrite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this nickelhexahydrite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch nickelhexahydrite with a known reference. Nickelhexahydrite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Nickelhexahydrite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Nickelhexahydrite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: emerald green, greenish-blue.
5
Look at form & habit
Crystal 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.

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: 2.03 g/cm³
Colors: Emerald Green Greenish-blue
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Crusts, Efflorescences, Granular, Rarely Prismatic Crystals
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Nickel-bearing Sulfide Deposits
Typical price: $20-100 per specimen

Where rockhounds find nickelhexahydrite

Classic worldwide localities

Kambalda, Western Australia
Lavrion, Greece
Copiapó, Chile
Schneeberg, Germany

Field-hunting tip

Look in oxidized zones of nickel-bearing sulfide deposits country — that is the host setting where nickelhexahydrite typically forms. If you start seeing morenosite, retgersite, goslarite in float, you are in the right ground. Field specimens usually show a crusts, efflorescences, granular, rarely prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify nickelhexahydrite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include emerald green, greenish-blue.

Where is nickelhexahydrite found?+

Notable localities include Kambalda, Western Australia; Lavrion, Greece; Copiapó, Chile; Schneeberg, Germany.

How much is nickelhexahydrite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is nickelhexahydrite safe to handle?+

It contains toxic constituents. Contains nickel, which is a potential allergen and toxic if ingested or inhaled as dust. Wash hands thoroughly after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like nickelhexahydrite?+

Nickelhexahydrite is most often confused with Hexahydrite, Morenosite, Retgersite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with nickelhexahydrite?+

Nickelhexahydrite commonly co-occurs with Morenosite, Retgersite, Goslarite, Melanterite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does nickelhexahydrite form in?+

Nickelhexahydrite typically forms in oxidized zones of nickel-bearing sulfide deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is nickelhexahydrite used for?+

Nickelhexahydrite is used in collector.

Find nickelhexahydrite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.