(Min.) A hydrous arsenite of cobalt, occuring in small red crystals, allied to erythrite.
roselite
roselite
[′rōz·ə‚līt] (mineralogy) (Ca,Co)2(Co,Mg)(AsO4)2·2H2O A pink or rose-colored, monoclinic mineral consisting of a hydrated arsenate of calcium, cobalt, and magnesium.