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.