An efficient and reliable technique for synthesizing sodalite is described. This new synthesis is termed “structure conversion method.” It converts a complex sodium-aluminosilicate structure into a sodalite structure while at the same time incorporating the alkali halide and activator compounds to form cathodochromic (CC) or photochromic (PC) sodalite in one step without requiring additional sensitizing procedure. Both PC and CC sodalites. of high quality have been synthesized by this method. The results of structural analysis, optical measurements, and electron beam excitation of these materials are presented. © 1974, The Electrochemical Society, Inc. All rights reserved.