Yellow green crystal plates of the rare Ni mineral reevesite from Clear Creek (Clear Creek, Picacho Peak, New Idria, San Benito County, California, United States of America). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Reevesite
Reevesite is an IMA-recognized mineral species in the carbonate class, with the chemical formula Ni₆Fe³⁺₂(CO₃)(OH)₁₆·4H₂O.
It crystallizes in the hexagonal crystal system. It is a member of the Hydrotalcite structural group.
Key properties: specific gravity 2.8–2.88; optically uniaxial.
IMA symbol Rvs, IMA status: approved, named in 1966.
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); on chromatite (Unst, Scotland).
It is found associated with Goethite, nickelian maghemite, jarosite, nickel-rich serpentine, apatite, lipscombite (Wolf Creek meteorite); violarite, ferroan trevorite, willemseite.
The mineral was named to honor Dr. Frank Reeves (1886–?), American geologist who discovered the Wolf Creek meteorite crater.