Ernienickelite is a very rare nickel manganese oxide mineral that typically occurs as soft, black powdery coatings or crusts within weathered ultramafic environments. Due to its unremarkable appearance and rarity, it is primarily sought by advanced systematic mineral collectors who focus on nickel-bearing supergene minerals.
Is this ernienickelite?
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 ernienickelite with a known reference. Ernienickelite 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: yellow-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic, submetallic to vitreous.
- 4Match the color rangeCompare against the expected color range: reddish black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: microscopic crystals, platy, rosette.
Often confused with
Ernienickelite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Ernienickelite leaves yellow-brown, Birnessite leaves brownish-black; luster reads metallic, submetallic to vitreous on Ernienickelite and dull on Birnessite.
How to tell apart: Asbolane is the harder of the two (Mohs 6 vs. 2); streak differs, so Ernienickelite leaves yellow-brown, Asbolane leaves black; luster reads metallic, submetallic to vitreous on Ernienickelite and earthy on Asbolane.
Often found alongside ernienickelite
Minerals reported to co-occur with ernienickelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NiMn₃O₇·3H₂O
- Mohs hardness
- 2
- Density
- 3.84 g/cm³
- Colors
- Streak
- Yellow-brown
- Luster
- Metallic, submetallic to vitreous
- Transparency
- Opaque, translucent in the thinnest plates
- Crystal system
- Trigonal
- Crystal habit
- Microscopic crystals, platy, rosette
- Cleavage
- {0001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In an intensely laterized ultramafic intrusion (Siberia, Western Australia); in the weathering zone of ultramafic rocks (Kamennyy Kobchik deposit, Russia)
Where rockhounds find ernienickelite
Classic worldwide localities
- SM7 open pit, near Siberia, 60 km north of Kalgoorlie, Western Australia
- Kamennyy Kobchik deposit, Kempirsay massif, Southern Ural Mountains, Russia
Field-hunting tip
Where it forms: In an intensely laterized ultramafic intrusion (Siberia, Western Australia); in the weathering zone of ultramafic rocks (Kamennyy Kobchik deposit, Russia). If you start seeing chalcedonic quartz, magnesite, serpentine in float, you are in the right ground. Typical habit: microscopic crystals, platy, rosette. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ernienickelite?+
Where is ernienickelite found?+
Is ernienickelite safe to handle?+
What rocks look like ernienickelite?+
What minerals are found with ernienickelite?+
What kind of rock does ernienickelite form in?+
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Find ernienickelite on the map
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