Coin-shaped metal disks bearing the image of Christ, Mary, or some saint, some shrine, or sacred event. They are blessed by the Church and are used to increase devotion. The use of medals is very ancient; many have been found in the catacombs, some with the chi-rho symbol. During the Middle Ages the pilgrims, on leaving a place of pilgrimage, were given medal tokens of the shrine. And today pilgrims to Rome, Lourdes, and elsewhere purchase medals that commemorate their visit. The efficacy of a metal depends on the faith of the person who wears or carries it, and on the Church's indulgenced blessing attached to this sacred object. There are innumerable medals approved by the Church. Among the most commonly used are the scapular and miraculous medals in honor of the Blessed Virgin.