Reference:
▪ Rastsvetaeva, R.K., Aksenova, S.M., Chukanov, N.V. (2012): Crystal structure of günterblassite, a new mineral with a triple tetrahedral layer.
Doklady Chemistry,
442, 57-62.
Structural formula: (K,Ca,Ba)
2(Fe,Ca,Mg,Na)[(Si,Al)
13O
25(OH)
4]·7H
2O.