The General Instruction of the Roman Missal, no. 302, contains the following statement: “The practice of placing relics of Saints, even those not Martyrs, under the altar to be dedicated is fittingly retained. However, care should be taken to ensure the authenticity of such relics.”
The tradition in the Roman liturgy of placing relics of martyrs or other saints beneath the altar is preserved when possible, but such relics should be of a size sufficient for them to be recognized as parts of human bodies; hence excessively small relics of one or more saints must not be placed beneath the altar.
Further, the greatest care must be taken to use relics that are authentic; it is better for an altar to be dedicated without relics than to have relics of doubtful authenticity placed beneath it.
Finally, the relics must be placed beneath the table of the altar, as the design of the altar permits.
While the altar at Assumption has the relic of a saint that goes back to the 1901 Church altar, the name of the saint or information about the relic has been lost in time. (9:37)