Poldervaartite

Ca_1.67H₂Mn_0.33O₅Si

Dai, Y. S.Harlow, G. E.McGhie, A. R.

American Mineralogist (1993) 78, 1082-1087

a=9.398Å   b=9.139Å   c=10.535Å

α=90°   β=90°   γ=90°