Citation: Vilminot, Serge; Baker, Peter J.; Blundell, Stephen J.; Sugano, Tadashi; Andr\'e, Gilles; Kurmoo, Mohamedally (2010). Giant Magnetic Hardness in the Synthetic Mineral Ferrimagnet K2CoII3(OH)2(SO4)3(H2O)2. Chemistry of Materials, 22, pp. 4090-.