Scope and Contents 'Correspondence re felspars.' Some papers in Russian and German. File includes notes on the influence of impurity of rubidium on A1-Si order in potash felspar (1965?). Correspondents include:Daniel E Appleman, 1962, re anorthite and 1972, re buddingtonite;Mr B B Baschkin, 1962;Bill Brown, Manchester University, 1962-4, re structure of anorthite, a plagioclase felspar;Dr O H J Christie, 1962;Joan R Clark;W J Cruickshank;Gai [Gabrielle Donnay?], 1959, re...