“[T]he process of ascertaining which of the thousands of skeletons belonged to a martyr was a nebulous one. If they found “M.” engraved next to a corpse, they took it to stand for “martyr,” ignoring the fact that the initial could also stand for “Marcus,” one of the most popular names in ancient Rome. If any vials of dehydrated sediment turned up with the bones, they assumed it must be a martyr’s blood rather than perfume, which the Romans often left on graves in the way we leave flowers today. The Church also believed that the bones of martyrs cast off a golden glow and a faintly sweet smell, and teams of psychics would journey through the corporeal tunnels, slip into a trance and point out skeletons from which they perceived a telling aura. After identifying a skeleton as holy, the Vatican then decided who was who and issued the title of martyr.”
Paul Koudounaris documenting how the bones of Christian martyrs were transformed into bejeweled relics and displayed in European churches in Heavenly Bodies.