#64
Cmca
Example – Tuhualite, (Na,K)2 Fe2(II)Fe2(III)Si12O30 • H2O
Tuhualite crystal structure, Locality: Mayor (Tuhua) Island, New Zealand
Merlino S
Science , 166 (1969) p.1399-1401
http://webmineral.com/data/Tuhualite.shtml
CIF
http://rruff.geo.arizona.edu/AMS/download.php?id=19044.cif&down=cif
SiO4 tetrahedra (orange)
Fe (red-brown)
Na (blue)
Position of H2O not determined in paper.
The Fascination of Crystals and Symmetry 