Retgersite is a rare nickel sulfate mineral typically formed as an alteration product in oxidized nickel deposits. It occurs as delicate, bright green efflorescences or crusts that are extremely sensitive to humidity and can dehydrate if stored improperly.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareRetgersite Group family

Retgersite

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

Is this retgersite?

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 retgersite with a known reference. Retgersite 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. Retgersite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Retgersite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: green, yellowish-green.
5
Look at form & habit
Crystal system: tetragonal. Typical habit: crusts, granular, acicular or fibrous aggregates.

Often confused with

Retgersite vs. its common look-alikes — and how to tell them apart in the field.

Often found alongside retgersite

Minerals reported to co-occur with retgersite. 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: 2.07 g/cm³
Colors: Green Yellowish-green
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Tetragonal
Crystal habit: Crusts, Granular, Acicular or Fibrous Aggregates
Cleavage: Good
Rarity: Rare
Uses: Collector
Host rock: Oxidized Zones of Nickel-rich Ore Deposits
Typical price: $20-150 per specimen

Where rockhounds find retgersite

Classic worldwide localities

Germany
Czech Republic
Canada
USA

Field-hunting tip

Look in oxidized zones of nickel-rich ore deposits country — that is the host setting where retgersite typically forms. If you start seeing morenosite, millerite, gersdorffite in float, you are in the right ground. Field specimens usually show a crusts, granular, acicular or fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify retgersite?+

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

Where is retgersite found?+

Notable localities include Germany; Czech Republic; Canada; USA.

How much is retgersite worth?+

Typical asking prices fall in the range of $20-150 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is retgersite safe to handle?+

It contains toxic constituents. Contains nickel, which is a known carcinogen and skin sensitizer. Handle with care, avoid inhalation of dust, and wash hands thoroughly after handling specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like retgersite?+

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

What minerals are found with retgersite?+

Retgersite commonly co-occurs with Morenosite, Millerite, Gersdorffite, Nickeline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does retgersite form in?+

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

What is retgersite used for?+

Retgersite is used in collector.

Find retgersite on the map

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