Hydrothermal chemistry of silicates. Part 22. Hydrated bariumsodium aluminosilicates

Abstract

A partial exploration has been made of crystallisation from tetramethylammonium ‘aluminosilicate’ solutions following addition of mixed barium chloride-sodium chloride solutions. Even small quantities of Ba²⁺ influence strongly which structures nucleate and crystallise, and so the system Na₂O–BaO–Al₂O₃–SiO₂–H₂O has also been further explored. Zeolites obtained included variants of offretite, zeolite A, zeolite L, zeolite M, faujasite, and gismondine. In addition a zeolite U10, probably belonging to the chabazite group, a barium aluminate, and an unidentified phase U11 have been obtained. The properties of U10 have been investigated. The hexagonal unit cell has a= 13.71 ± 0.03 and c= 15.57 ± 0.04 Å.