AM_Piemontite_10 Formula: Ca2 (Al1.97 Mn1.03) Si3 O13 H Name: Piemontite Unit cell: 8.86 5.6818 10.167 90.0 115.511 90.0 , V=461.91 Space group: P121/M1 (11)

Nagashima M , Akasaka M , American Mineralogist , 89 (2004) p.1119-1129, An X-ray Rietveld study of piemontite on the join, Ca2Al3Si3O12(OH) - Ca2Mn3+3Si3O12(OH) formed by hydrothermal synthesis, Sample: q = 1.1, p = 1.03, Synthesis at P=350 MPa, T=500 C