Recommended nomenclature for zeolite minerals: report of the subcommittee on zeolites of the International Mineralogical Association, Commission on New Minerals and Mineral Names

This report embodies recommendations on zeolite nomenclature approved by the International Mineralogical Assocn., Commission on New Minerals and Mineral Names (IMA,CNMMN). In a working definition of a zeolite mineral used in this paper, structures contg. an interrupted framework of tetrahedra are accepted where other zeolitic properties prevail, and complete substitution by elements other than Si and Al is allowed. Sep. species are recognized in topol. distinctive compositional series in which different extra-framework cations are the most abundant in at. proportions. To name these, the appropriate chem. symbol is attached by a hyphen to the series name as a suffix, except for the names harmotome, pollucite and wairakite in the phillipsite and analcime series. Differences in space-group symmetry and in order-disorder relationships in zeolites having the same topol. distinctive framework do not in general provide adequate grounds for recognition of sep. species. Zeolite species are not to be distinguished solely on the ratio Si: Al except for heulandite (Si: Al < 4.0) and clinoptilolite (Si: Al ≥ 4.0). Dehydration, partial hydration, and overhydration are not sufficient grounds for the recognition of sep. species of zeolites. Use of the term "ideal formula" should be avoided in referring to a simplified or averaged formula of a zeolite. Newly recognized species in compositional series are as follows: brewsterite-Sr, -Ba, chabazite-Ca, -Na, -K, clinoptilolite-K, -Na, -Ca, dachiardite-Ca, -Na, erionite-Na, -K, -Ca, faujasite-Na, -Ca, -Mg, ferrierite-Mg, -K, -Na, gmelinite-Na, -Ca, -K, heulandite-Ca, -Na, -K, -Sr, levyne-Ca, -Na, paulingite-K, -Ca, phillipsite-Na, -Ca, -K, and stilbite-Ca, -Na. Key refs., type locality, origin of name, chem. data, IZA structure-type symbols, space-group symmetry, unit-cell dimensions, and comments on structure are listed for 13 compositional series, 82 accepted zeolite mineral species, and three of doubtful status. Herschelite, leonhardite, svetlozarite, and wellsite are discredited as mineral species names. Obsolete and discredited names are listed.