In this study quartz is used as the only source of silica in the synthesis of several zeolitic phases at low temperatures. The study is concerned primarily with the kinetics of crystallization of zeolite HS (a hydroxysodalite) as related to the rate of dissolution of the quartz reactant. The two rates are found to be essentially equal. The crystals nucleate and grow on the surface of the quartz reactant. The results support the theory of zeolite crystallization from solution (rather than solid-solid transformation). The activation energy for the process is 21.7 kcal/mol. The rate-limiting step in the dissolution of the quartz reactant is believed to occur as bonds are broken on the surface of the dissolving crystals; this is consistent with the surface-diffusion and step-growth theory of crystal growth. An interesting side result of the study was the synthesis for the first time using quartz as the only source of silica of the molecular sieve zeolites, zeolite A and zeolite X.