Koenenite

Al_0.364H₂Mg_0.636O₂

Allmann, R.Lohse, H. N.Hellner, E.

Zeitschrift fur Kristallographie (1968) 126, 7-22

a=3.052Å   b=3.052Å   c=10.880Å

α=90°   β=90°   γ=120°