Microlite 0.522cts Trillion Cut 4.33 x 4.37mm from from Skardu – Pakistan. h5-5.5 Y11634
The A site, therefore, may host Na, Ca, Sr, Pb2+, Sn2+, Sb3+, Y, U, □, or H2O or, less frequently Ag, Mn, Ba, Fe2+, Bi3+, Ce (and other REE), Sc or Th.
X typically is O but can include subordinate OH and F.
Z typically is an anion, but can also be a vacancy, H2O, or a very large (>> 1.0 Å) monovalent cation (site 8b). Examples are OH–, F, O, □, H2O, K, Cs, Rb.
The symbols m, w, and n represent parameters that indicate incomplete occupancy of the A, X and Z sites, respectively. (Atencio et al. 2010).