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 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Ernienickelite leaves a yellow-brown streak.
- 3Read the lusterHold the specimen under a strong light. Ernienickelite typically shows a metallic to submetallic to vitreous luster.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive, coatings, crusts.
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 to submetallic to vitreous on Ernienickelite and dull on Birnessite.
How to tell apart: Asbolane is the harder of the two (Mohs 5-6 vs. 2-3); streak differs, so Ernienickelite leaves yellow-brown, Asbolane leaves black; luster reads metallic to submetallic to vitreous on Ernienickelite and dull 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
- 2-3
- Density
- 3.55 g/cm³
- Colors
- Streak
- Yellow-brown
- Luster
- Metallic to Submetallic to Vitreous
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Massive, Coatings, Crusts
- Cleavage
- {0001}, Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Weathered Ultramafic Rocks
Where rockhounds find ernienickelite
Classic worldwide localities
- Bulgunda, Western Australia
Field-hunting tip
Look in weathered ultramafic rocks country, the host setting where ernienickelite typically forms. If you start seeing goethite, asbolane, nontronite in float, you are in the right ground. Field specimens usually show a massive, coatings, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ernienickelite?+
Where is ernienickelite found?+
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
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
