A phosphate mineral typically found as greenish or yellowish-white prismatic crystals and crystal aggregates.
Fairfieldite is a hydrated phosphate of calcium, manganese, and iron, Ca₂(Mn,Fe)(PO₄)₂·2H₂O. Crystal system: triclinic.
Late 19th century. From the name of FairfieldCounty, Connecticut, where the mineral was first identified + -ite.