AM_Umbite
Formula: K2 (Zr.86 Ti.14) Si3 O10 H
Name: Umbite
Unit cell: 10.207 13.241 7.174 90.0 90.0 90.0 , V=969.57
Space group: P212121 (19)

Ilyushin G D , Izvestiya Akademii Nauk SSSR Neorganicheskie Materialy , 29 (1993) p.971-975, New data on the crystal structure of umbite K2ZrSi3O9*H2O