An amorphous powder useful as a precursor for the preparation of crystalline aluminosilicates is prepared by forming a sodium aluminum silicate water mixture whose composition falls within specified ranges for forming sodium zeolite A. By dehydrating the mixture with a water miscible solvent prior to aging and crystal formation, an amorphous powder is recovered for future use. Upon subsequent treatment the amorphous powder can be converted to crystalline aluminosilicates including type 3A, 4A, 5A, X and Y.