The procedure was designed for the simple, rapid determination of the Fe(II)/Fe(III) ratio in glass samples. The procedure consists of the following steps: dissolution of the pulverized glass sample in a sulfuric-hydrofluoric acid mixture, containing ammonium vanadate, which preserves the Fe(II) content; addition of boric acid to destroy iron-fluoride complexes, making the iron available for color formation with Ferrozine; addition of pH 5 buffer and Ferrozine reagent to form the magenta-colored ferrous-Ferrozine complex, with measurement of the absorbance for the determination of Fe(II) content; and, addition of ascorbic acid to reduce Fe(III) to Fe(II), with a second absorbance measurement that determines total Fe. Directions for the preparation of glass from non-radioactive sludge samples are provided. The analysis of this prepared glass for the Fe(II)/Fe(III) ratio is an indication of the ratio that would be in a plant batch of glass if made from this sludge.