Gismondine-Sr, recently discovered in the Hatrurim Complex in Israel, has been recognised in a xenolith sample from the Bellerberg volcano in Germany. The empirical crystal-chemical formula indicates elevated K content: (Sr1.74Ca1.05Ba0.09K1.56Na0.49)∑4.93[Al7.98Si8.06O32]•9.62 H2O. Additionally, Ba-rich gismondine and amicite have been found in the low-temperature mineral association of the pyrometamorphic rock from the Hatrurim Complex. The Raman spectra of the studied zeolites and the crystal structure of gismondine-Sr from the second occurrence are presented. An insightful review of zeolites with GIS framework-type structure led to the following conclusions: 1) garronite-Na and gobbinsite are equivalent and constitute a solid-solution with garronite-Ca; 2) gismondine-Ca, -Sr, and amicite belong to one mineral series; 3) two zeolites series with different R-factor (defined as Si/(Si+Al+Fe)) can be distinguished within GIS topology: the garronite series (R > 0.6) including garronite-Ca and