AM_Plancheite
Formula: Cu8 Si8 O27 H6
Name: Plancheite
Unit cell: 19.043 20.129 5.269 90.0 90.0 90.0 , V=2019.69
Space group: PCNB (60)

Evans H T , Mrose M E , American Mineralogist , 62 (1977) p.491-502, The crystal chemistry of the hydrous copper silicates, shattuckite and, plancheite, Note: sample is from Rioja, Argentina