Gemolo's
relics were determined to be authentic by a commission set up in 1941, which was headed by Cardinal
Ildefonso Schuster. The saints are mentioned in two historical sources: the
Liber Notitiae Sanctorum Mediolani, a manuscript of the 13th century, attributed to Goffredo da Bussero and conserved in the archepiscopal archives of
Milan; and the Gospel of the Passion, which is guarded in the archives of the Abbey of Ganna. Rocks stained red with a particular
algae found near the Abbey of Ganna were identified with the drops of Gemolus' blood in popular tradition. This led the monks to construct a second
oratory some distance from the road in the 14th century to accommodate veneration of this particular natural phenomenon. ==Notes==