Reevesite is a rare nickel-iron carbonate mineral typically forming as thin, platy crystals or earthy crusts in the oxidation zones of nickeliferous ores. Its distinct yellow to yellow-green color and pearly luster are key identifiers, often found associated with serpentine or goethite. It is primarily a collector's mineral due to its rarity and delicate nature.
Is this reevesite?
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 reevesite with a known reference. Reevesite 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.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: green yellow, light yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Reevesite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Reevesite leaves yellow, Hydrotalcite leaves white; luster reads pearly on Reevesite and satiny to greasy or waxy on Hydrotalcite.
How to tell apart: Streak differs, so Reevesite leaves yellow, Meixnerite leaves white.
How to tell apart: Streak differs, so Reevesite leaves yellow, Woodwardite leaves light blue.
Often found alongside reevesite
Minerals reported to co-occur with reevesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni₆Fe³⁺₂(OH)₁₆(CO₃)·4H₂O
- Mohs hardness
- 2
- Density
- 2.8-2.88 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Pearly
- Transparency
- Semitransparent
- Crystal system
- Trigonal
- Crystal habit
- Platy crystals, crusts, radial aggregates
- Cleavage
- Perfect basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An alteration product of a highly weathered iron-nickel meteorite (Wolf Creek meteorite); altered from violarite in nickel ore at a contact between quartzite and ultramafic rocks (Bon Accord, South Africa)
Where rockhounds find reevesite
Classic worldwide localities
- Victor claim, Clear Creek, San Benito Co., California, USA
- Fremont district, Hidalgo and Luna Co., New Mexico, USA
- Barrett Camp, Dragoon Mountains, Cochise Co., Arizona, USA
- Found three km west of the Scotia talc mine, Bon Accord area, Barberton, Transvaal, South Africa
- Hagdale quarry, Unst, Shetland Islands, Scotland
- Ca’ de Ladri, Emilia-Romagna, Italy
Field-hunting tip
Where it forms: An alteration product of a highly weathered iron-nickel meteorite (Wolf Creek meteorite); altered from violarite in nickel ore at a contact between quartzite and ultramafic rocks (Bon Accord, South Africa). If you start seeing goethite, nickelian maghemite, jarosite in float, you are in the right ground. Typical habit: platy crystals, crusts, radial aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify reevesite?+
Where is reevesite found?+
Is reevesite safe to handle?+
What rocks look like reevesite?+
What minerals are found with reevesite?+
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Find reevesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
