Ô Marie, conçue sans péché, priez pour nous qui avons recours à vous ("O Mary, conceived without sin, pray for us who have recourse to thee")
These are the words written on the medallion of the Miraculous Medal, called also the Medal of Immaculate Conception.
Front side:
Mary stands on a globe – Mary bestowing graces upon the Earth and mankind, assumed into Heaven, describing the original vision, Catherine said Mary appeared radiant as a sunrise, "in all her perfect beauty"
Crushes the serpent's head underfoot – reference to Genesis 3:15, Mary is engaged in the spiritual battle against evil and Satan (serpent), she protects from evil.
Rays of light from her hands and rings – symbolizing graces from Mary as a Mediatrix, Mary told Catherine that the rays "symbolize the graces I shed upon those who ask for them"
"O Mary conceived without sin" (part of the prayer) – reference to Mary as the Immaculate Conception.
Source
Reverse side:
The large letter "M" – first letter of the name "Mary"
The Cross – Jesus Christ's cross as an act of redemption for mankind
The crossbar - the foot of the Cross, interlacing of the "M" and the crossbar and the Cross shows Mary's close involvement with her son in the mission of human salvation, and standing at the foot of the cross during in his redemptive sacrifice.
12 stars – the Twelve Apostles and the Church, and the vision of John the Apostle in Revelation 12:1: "And 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", symbolizing the Woman of Apocalypse and Queen of Heaven
Left heart – the Sacred Heart of Jesus; flaming heart of divine love for mankind, pierced by the lance, encircled by the crown of thorns, surmounted by a cross and bleeding
Right heart – the Immaculate Heart of Mary; flaming heart of maternal love, pierced by a sword referencing Simeon's prophecy in Luke 2:35.
Source
At the bottom of the image of Mary is the year 1830. This was the year that the Virgin Mary appeared before Catherine Laboure.
The medallion is bigger than a dime. It is made of a non-magnetic metal. I used a slide tester, along with a 1964 Roosevelt Dime (as my control), and they both slowly went down the slide together at the same speed! My other medallions are not silver were just stuck in one place on the slide tester.
The other non-magnetic metals are gold, silver, copper, and brass. This medallion is neither copper or brass.
I shall attach this medallion to my silver and pearl charm bracelet along with the 1877 Seated Liberty Silver Dime, the Silver Key, and the Silver California Prospector.
Thank you so much 
I received this medallion along with other fun things as well, which I will feature when appropriate.
Until then!
Reference
https://miraculousmedal.org/welcome/story-of-st-catherine/
https://www.ewtn.com/catholicism/library/st-catherine-laboure-and-the-miraculous-medal-5667
https://en.wikipedia.org/wiki/Miraculous_Medal#Properties_of_the_medal
https://www.simplycatholic.com/what-are-sacramentals/
I hope to see you again soon!
Hugs and Kisses 🥰🌺🤙!!!!
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