Interesting Erythrite Crystals from Spain Minerals 3:24 AM A+ A- Print Email Juan Miguel Segura’s Photo ErythriteFormula: Co3(AsO4)2·8H2O System: Monoclinic Colour: Crimson to peach red, ... Hardness: 1½ - 2½ Member of: Vivianite Group From La Encontrada Mine, Molvizar, Granada, Andalusia, Spain