Abstract: Superconducting precursors, which can be made into metal oxide superconductors such as YBa.sub.2 Cu.sub.3 O.sub.6+x, and a process for their manufacture by the coprecipitation of 1-2-3 nitrates using inexpensive precipitating agents such as alkali hydroxides, carbonates and bicarbonates. The process involves preparing a stoichiometric mixture of Y, Ba and Cu nitrates, which is then combined with a solution containing an excess of NaOH/K.sub.2 CO.sub.3, KOH/K.sub.2 CO.sub.3, NaOH/Na.sub.2 CO.sub.3, or KOH/Na.sub.2 CO.sub.3, which causes the precipitation of the precursor. The suspension containing the precipitate is filtered and then washed wiThe invention of this application was made and conceived at least in part with United States Government support and the United States Government has certain rights in the invention.