Guidottiite

Fe_1.656H₄Mg_0.537Mn_1.854O₉Si_0.953

Wahle, M. W.Bujnowski, T. J.Guggenheim, S.Kogure, T.

Clays and Clay Minerals (2010) 58, 364-376

a=5.5472Å   b=5.5472Å   c=14.296Å

α=90°   β=90°   γ=120°