Abstract: An improved method is provided for preparing a crystalline aluminosilicate zeolite having a high silica/alumina mole ratio which comprises adding a source of aluminum ions to a silica-rich amorphous reaction medium at a rate whereby the concentration of aluminum ions in the amorphous phase of the preparation is maintained at steady state during crystallization. Crystallization time is substantially shortened by the present improved method and zeolites synthesized by way of the present improved method exhibit improved steam stability.Also provided are improved crystalline aluminosilicate zeolites prepared by way of the present improved method of synthesis and organic compound conversion therewith.