The following was provided to my Uncle Michael Angelo Petrocco Junior by the Historical Research Center.
The Italian surname Petrocco is of patronymic origin. Patronymic surnames are those names which derive their origin from the personal name of the father of the initial bearer of the name. In this instance, the surname Petrocco is derived from the Italian personal name Pietro. Thus, the surname Petrocco signifies son or descendant of Pietro. The personal name Pietro is derived from the Latin Petrus, from the Greek Petros, a translation of the Aramaic Kephos meaning "rock," the name given to Simon by Jesus of Nazareth in the Christian New Testament. The particular reference is translated in English as, "Thou are Peter and upon this rock..." - a direct translation of the Latin, "Petrus es et super hanc petram..."
The surname Petrocco has many variants, among them Petrucci, Pietro, Petro, Piero, and Pietruccio. The earliest references to the surname Petrocco or to a variant include the noble Petrucci family of Florence, whose ancestral house was located in the town of the same name (Florence). Notable members of this family were twelve priors and one Standard-bearer, who held their offices between the years 1425 and 1522. Also notable families were the Petrucci family of Roma and the Pitro (or Pitru) family of Messina.
BLAZON OF ARMS: Argent (silver or white) background - a cross gules (red) between four mullets (stars) azure (blue) - in chief (at the top) a double-headed eagle or (gold).
TRANSLATION: Argent (silver or white) signifies peace and sincerity. Gules (red) denotes magnanimity and military fortitude. Azure (blue) signifies truth and loyalty. Or (gold) denotes generosity and elevation of mind. The cross is representative of the Christian faith and the love of God for sinful man.
CREST: Three ostrich plumes argent (silver or white).
ORIGIN: Italy.