AM_Piemontite_13
Formula: Ca2 (Al1.75 Mn1.25) Si3 O13 H
Name: Piemontite
Unit cell: 8.8591 5.7039 10.1827 90.0 115.548 90.0 , V=464.24
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 = 1.75, p = 1.26, Synthesis at P=200 MPa, T=500 C