Beudandite is a secondary mineral occurring in the oxidized zones of polymetallic It is a lead , sulfate : PbFe3(OH)6SO4AsO4.
Beudantite is in a subgroup of the alunite group. It is the arsenate analogue of the phosphate corkite. Beudantite also forms a solid-solution and plumbojarosite
It crystallizes in the trigonal and shows a variety of crystal habits including tabular, acute rhombohedral, pseudo-cubic and pseudo-cuboctahedral.
It occurs in association with carminite , mimetite , arseniosiderite, olivenite, anglesite