Martin de Porres was born in Lima, Peru in abt 1579. He died in 1639. His cause was introduced almost immediately because of “startling miracles” and a life of intense prayer and spirituality–recognized even within his own lifetime. Rome moves slowly, as we all know, and his canonization did not take place until 1962.
It is common, even obligatory, for a major relic of those introduced to the cause of sainthood to be separated from the body and transmitted to Rome. Even the body of Marie-Bernadette Soubirous (1844-1879), which is preserved incorrupt in the convent of her order at Nevers, France, had a major relic removed for the canonization process. Since there is no record of incorrupt preservation for Martin de Porres, we can conclude that over three centuries nature took its course and the relics which remain from the body are mostly human bone. Of these the skull is the most clearly recognized and the most likely to have remained intact.
Following canonization, the relics may be venerated by the faithful giving due regard for canon law. To my knowledge there is no “master list” of who has which relics for every saint who has ever lived, but each altar stone in every Catholic Church throughout the world is entitled to be erected on the relics of the martyrs and other saints. The relics may be removed periodically for exposition and veneration by the faithful, as our parish did on November 1.
The ecclesiastic approbation provided with your card indicates it is, indeed, a third class relic from having been touched to a known first class relic.
en.wikipedia.org/wiki/Bernadette_Soubirous has some nice photographs of the other referenced Saint.
