Example – Tincalconite, Na6[B4O5(OH)4]3 • 8 H2O
Named for tincal (borax) and konos “powder” in allusion to the minerals composition and appearance.
The crystal structure of Tincalconite
Giacovazzo C, Menchetti S, Scordari F
American Mineralogist 58 (1973) 523-530
BO3 trigonal-planar units and BO4 tetrehedra (pink)
NaO6 distorted octahedra (orange)
Water partially disordered.