Switzerite

Switzerite is a mineral with the chemical formula of (Mn)₃(PO₄)₂·7H₂O. The mineral was named after George Switzer, former Curator of Minerals at the US National Museum.The mineral is monoclinic prismatic, meaning that it has one mirror plane, one 2-fold rotation axis which is perpendicular to the mirror plane and a center of symmetry. Switzerite is a part of the monoclinic space group P 2₁/a. For its optical properties, Switzerite is classified as anisotropic, has a low surface relief and birefringence of δ = 0.020.