Lead feldspar

Lead feldspar, PbAl2Si2O8. and solid solutions of the system PbAl2Si2O8—KAlSi3O8 have been synthesized. Lattice parameters of PbAl2Si2O8 are: a = 8.415 ± 0.005, b = 13.063 4; 0.006, c = 7.162 ± 0.004 Å, ß = 115°8′ ± 2′. Possible space groups are C2/cm, C2 and Cm. For compounds of feldspar type a linear relationship between the lattice constant a and the corresponding cation radii was found. The lead feldspar fits well into this relation. © 1971, Walter de Gruyter. All rights reserved.