In the Collegiata di Santa Maria Assunta in Amaseno, a small town south of Rome, there’s a simple glass ampulla containing a dark, coagulated substance traditionally identified as the blood of St. Lawrence.
St. Lawrence—the Roman deacon and martyr—was executed on August 10, traditionally dated to the year 258. And this relic is no recent discovery: it has been documented in Amaseno since at least the consecration of the church in 1177.
The consecration documents describe it in Latin as de pinguedine S. Laurentii Martyris—literally, “of the fat of St. Lawrence the Martyr.” That detail is important. The relic has not historically been described as a tidy vial of pure blood, but as a mixture of material associated with the saint’s martyrdom.
Inside are what appear to be blood, fat, ashes, and even a small fragment of skin.
Here’s where it gets really fascinating.
For most of the year, the contents of the ampulla appear solid, dark, and coagulated. But around St. Lawrence’s feast on August 10, the substance traditionally undergoes a dramatic transformation: the dark mass becomes liquid and bright red, with the blood becoming visibly distinguishable from the other material in the ampulla.
Historical accounts say the phenomenon has
