#63
Cmcm
Example – Ferruccite, NaBF4
Named for Ferruccio Zambonini (1890 – 1932), an Italian mineralogist and geologist. Most of his time he worked on the geology and mineralogy of Mount Vesuvius.
Refinement of the structure of NaBF4, Locality: synthetic
Brunton G
Acta Crystallographica, Section B , 24 (1968) p.1703-1704
http://webmineral.com/data/Ferruccite.shtml
CIF
http://rruff.geo.arizona.edu/AMS/download.php?id=10335.cif&down=cif
BF4 tetrahedra (blue)
Sodium (gold)
The Fascination of Crystals and Symmetry 