Our Lady visited Saint Catherine Labouré on November 27th, 1830, and Saint Catherine noticed rays of light flowed from the rings (made of precious stones) on her fingers. However, some of the stones on the rings did not shine. Mary explained: "These rays symbolize the graces I shed upon those who ask for them. The gems from which rays do not fall are the graces for which souls forget to ask."
Mary then spoke of the medal which she was requesting with these words: "All who wear it will receive great graces; they should wear it around the neck. Graces will abound for persons who wear it with confidence."
The medal is a visible sign of the wearer's devotion to Mary and to her Son, Jesus.
THE MEANING OF THE MEDAL
THE FRONT: On the front of the Miraculous Medal, Mary stands on a globe, which represents the earth; a serpent is crushed beneath her feet. This image shows Mary in her role as "Queen of Heaven and Earth." The serpent represents Satan, who was defeated by Mary's obedience to God, which gave us our Savior. The rays coming from her hands symbolize the graces Mary gives to those who ask her for them. 1830 is the year that the Blessed Mother appeared to St. Catherine Labouré and requested the making of this medal.
THE REVERSE: On the reverse side of the Miraculous Medal is a cross and the letter "M." The cross represents Christ's sacrifice for our salvation, while the bar under the cross stands for the earth. The "M" stands for "Mary" and her true devotion both to Jesus and to her children on earth. The two hearts are the Most Sacred Heart of Jesus and the Sorrowful Heart of Mary. The image is surrounded by twelve stars. The stars represent both the twelve Apostles and the verse from the Book of Revelation: "A great sign appeared in heaven, a woman clothed with the sun, and the moon under her feet, and on her head a crown of twelve stars." (Revelation 12:1)