[Question]{.underline}: Where do altar stones come from, and how do we know which saints’ relics they contain?
[Answer]{.underline}: An altar stone is technically called a portable or moveable altar, as distinct from a fixed or immoveable altar, for it can be removed from the wooden or plaster structure in which it has been fixed. However, an altar stone must be consecrated, as are fixed altars, according to the ceremony contained in the Roman Pontifical. Any bishop can consecrate an altar stone, and the bishops of the Society of Saint Pius X do this regularly to add to the altar stones consecrated before Vatican II that we use when we can.
It is usually not possible to know which saints’ relics are contained in an altar stone. The rubrics require that the relics from the bodies of at least two martyr-saints be contained in a consecrated altar, whether it be moveable or fixed. There must be a certificate of authenticity for each relic, but each certificate must be enclosed with the relics and three grains of incense in the sepulcher that is cut out from the upper surface of the altar stone. A natural stone cover is placed over the sepulcher to close it off, and is cemented in place. Thereafter there is no way of knowing what is inside without breaking the cement seal and lifting off the cover, which causes the altar stone to lose its consecration.
Altar stones that have recently been consecrated usually have a certificate of consecration from the consecrating bishop, attesting to the names of the martyr-saints whose relics are contained in the stone (if known). However, with time such authenticates are frequently lost, and they are not necessary for an altar stone to be presumed as consecrated and used as such, as we read in Matters Liturgical, 10^th^ ed., p. 119: “The consecration of a sacred stone is sufficiently attested to by the marks of the burnt incense on the crosses and by the cement securing the cover of the sepulcher. It is, however, customary to attach a document signed by the consecrator to the cloth in which the stone is wrapped.”
Answered by Father Peter Scott, SSPX.