Honessite is a rare secondary nickel mineral typically found as thin, green to brown coatings or delicate, radiating crusts in the oxidized zones of ore deposits. It is most frequently encountered by collectors associated with millerite in localities like the Wisconsin lead-zinc districts. Due to its softness and delicate habit, it requires careful handling.
Is this honessite?
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 honessite with a known reference. Honessite 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. Honessite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Honessite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: green, brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Honessite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Honessite leaves yellow, Morenosite leaves white; luster reads pearly on Honessite and vitreous on Morenosite.
How to tell apart: Streak differs, so Honessite leaves yellow, Retgersite leaves pale green; luster reads pearly on Honessite and vitreous on Retgersite.
How to tell apart: Streak differs, so Honessite leaves yellow, Nickelhexahydrite leaves white; luster reads pearly on Honessite and vitreous on Nickelhexahydrite.
Often found alongside honessite
Minerals reported to co-occur with honessite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ni,Fe³⁺)₆(OH)₁₆(SO₄,CO₃)·4H₂O
- Mohs hardness
- 2
- Density
- 2.28 g/cm³
- Streak
- Yellow
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy Crystals, Crusts, Radial Aggregates
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Nickel-bearing Sulfide Deposits
Where rockhounds find honessite
Classic worldwide localities
- Linden, Wisconsin, USA
- Agua Blanca, Spain
- Kambalda, Australia
Field-hunting tip
Look in oxidized zones of nickel-bearing sulfide deposits country, the host setting where honessite typically forms. If you start seeing millerite, goethite, quartz in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify honessite?+
Where is honessite found?+
Is honessite safe to handle?+
What rocks look like honessite?+
What minerals are found with honessite?+
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Find honessite on the map
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