AM_Chapmanite_1 Formula: Sb Fe2 Si2 O9 H Name: Chapmanite Unit cell: 5.225 8.997 7.78 90.0 101.71 90.0 , V=358.12 Space group: C1M1 (8)

Ballirano P , Maras A , Marchetti F , Merlino S , Perchiazzi N , Powder Diffraction , 13 (1998) p.44-49, Rietveld refinement of chapmanite SbFe2Si2O8OH,, a TO dioctahderal kaolinite-like mineral, Locality: Tafone mine, Tucsany, Italy