Ca4F2O7Si2
Saburi, S.Kawahara, A.Henmi, C.Kusachi, I.Kihara, K.
Mineralogical Journal (1977) 8, 286-298
a=7.518Å b=10.521Å c=10.906Å
α=90° β=70.7° γ=90°
Ca3O7Si2
Saburi, S.Kusachi, I.Henmi, C.Kawahara, A.Henmi, K.Kawada, I.
Mineralogical Journal (1976) 8, 240-246
a=10.557Å b=8.885Å c=7.858Å
α=90° β=119.586° γ=90°