A process for producing a synthetic quartz glass powder which is substantially free of carbon contaminant, for reduced bubble density and improved stability of articles made from the synthetic quartz glass during fusion molding by maintaining the synthetic silica powder in an oxidizing environment, e.g., an atmosphere comprising at least 3 vol. % ozone at a temperature of less than 1400.degree. C., causing carbon containing compounds to be reduced to less than 10 ppm.