What is "pecoraite"

n. (context mineralogy English) A monoclinic-prismatic dark green mineral containing hydrogen, nickel, oxygen, and silicon.

Pecoraite is a Nickel silicate mineral and a member of the serpentine group. It is monoclinic and has a chemical composition of Ni(SiO)(OH) It is associated with the weathering-and-or oxidation of meteorites or nickel sulfide minerals such as Millerite. It is also found as shears in ultramafic rocks. Pecoriate is typically a green, lime green, or bluegreen mineral with a waxy, or earthy luster and a mohs hardness of 2.5. Common textural habits associated with Pecoraite are curved plates, spirals and tubes. It can also be granular and massive.