Our Lady appeared to St. Catherine Laboure in 1830, commissioning St. Catherine to have a medal struck in her honor. St. Catherine was given the mission to fashion the medal after the image Mary revealed to her. In the Miraculous Medal Mary is standing on a globe as queen of heaven and earth, crushing the head of a serpent beneath her foot (Gen. 3:15) . Around the image are the words, "Oh Mary conceived without sin, pray for us who have recourse to Thee." The reference to Mary conceived without sin supports the dogma of the Immaculate Conception of Mary. On the reverse of the Miraculous Medal are twelve stars (Rev. 12:1), the Sacred Heart of Jesus next to the Immaculate Heart of Mary, and an intertwined cross and an "M". With this image Mary is sharing her special role in salvation history and as mother of the Church. The two hearts represent the love of Jesus and Mary. Ever since it's construction, the Miraculous Medal has been associated with many graces and miracles. In addition, Mary promised special graces to those who wear the Miraculous Medal necklace.
Dimensions and Specifications