Altar Stone

An altar stone is a piece of natural stone containing relics in a cavity and intended to serve as the essential part of an altar for the celebration of Mass in the Roman Catholic Church. Consecration by a bishop of the same rite was required. In the Byzantine Rite, the antimension, blessed and signed by the bishop, serves a similar function. In contrast to the Jewish practice of building altars of several stones, the earliest Christian altars were of wood and shaped like ordinary house tables, a practice that continued until the Middle Ages. However, a preference for more durable materials led to church enactments in the West against wooden altars, but not in the East. The earliest stone altars were the tombs of martyrs, over which Mass was sometimes offered, either on a stone slab enclosing the tomb or on a structure placed above it. When the first custom-built Christian basilicas were built, the altar of the church was placed directly above the tomb of a martyr, as in the case of St. Peter's Basilica and the Basilica of Saint Paul Outside the Walls.