Pecoraite from Eden, Vermont
CategorySilicate mineral
(repeating unit)
IMA symbolPco[1]
Strunz classification9.ED.15
Crystal systemMonoclinic
Unknown space group
ColorGreen, blue-green yellow-green
Mohs scale hardness2.5–3
LusterWaxy, earthy
StreakPale green
Specific gravity3.084

Pecoraite is a nickel silicate mineral and a member of the serpentine group. It was named after geologist William Thomas Pecora. It is monoclinic and has a chemical composition of Ni3(Si2O5)(OH)4. It is associated with the weathering-and-or oxidation of meteorites or nickel sulfide minerals such as millerite. It is also found in altered ultramafic rocks.[2] Pecoraite is typically a green, lime green, or bluegreen mineral with a waxy, or earthy luster and a mohs hardness of 2.5.[3] Common textural habits associated with pecoraite are curved plates, spirals and tubes. It can also be granular and massive.

See also


  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ "Mineralogy Database". Mindat. Retrieved 2013-03-21.
  3. ^ "Webmineral". Retrieved 2013-03-21.