- Cooper M A, Abdu Y A, Ball N A, Černý P, Hawthorne F C, Kristiansen R (2012) Aspedamite, ideally ☐ 12 (Fe 3+ ,Fe 2+ ) 3 Nb 4 [Th(Nb,Fe 3+ ) 12 O 42 ]{(H 2 O),(OH)} 12 , a new heteropolyniobate mineral species from the Herrebøkasa Quarry, Aspedammen, Østfold, Southern Norway: description and crystal structure, The Canadian Mineralogist 50, 793-804