MAXIMA OF ALKALI FELDSPARS AND AN EASY METHOD TO DETERMINE T1 AND T2 SITE OCCUPANCIES

Hovis (1986) reported on the variation of unit-cell dimensions and volumes as a function of both com-position and AI-Si distribution for five alkali feld-spar ion-exchange series. Four of the series are topochemically monoclinic, and range from a rela-tively ordered series based on an "adularia " parent feldspar to a highly disordered series based on anal-bite. The fifth is a highly ordered topochemically triclinic series based on Amelia low albite. Details on the parent materials used to make these series, and on the synthesis histories and chemical compo-sitions of all series members, were presented in Hovis (1986). Hovis (1986) emphasized the characterization of structural state and determination of mole fractio