Népouite
Népouite is a rare nickel-rich member of the serpentine subgroup of phyllosilicate minerals. Its chemical formula is (Mg,Ni)3Si2O5(OH)4. Népouite is typically apple-green to greenish-white in color and forms as a secondary mineral through the alteration of ultramafic rocks, particularly nickel-bearing serpentinites. It is often found in association with other nickel minerals such as garnierite (a general term for hydrous nickel silicate mixtures). Népouite's name originates from the locality where it was first discovered: Népoui, New Caledonia. It is a relatively soft mineral, with a Mohs hardness of around 3-4. Népouite is an important ore mineral for nickel, though its occurrence is not widespread enough to be considered a major source globally.