Citation: Roberts, A. C.; Cooper, M. A.; Hawthorne, F. C.; Criddle, A. J.; Stirling, J. A. R. (2002). Sewardite, CaFe2(AsO4)(OH)2, the Ca-analogue of carminite, from Tsumeb, Namibia: Description and crystal structure. The Canadian Mineralogist, 40, pp. 1191-1198.