This is a tiny 14K gold plated Miraculous Medal measuring 10x16mm. It hangs from an 18 inch Italian 18K gold vermeil chain.

The MIRACULOUS MEDAL (French: Médaille miraculeuse), also known as the Medal of the Immaculate Conception, is a medal, the design of which was originated by Saint Catherine Labouré following her vision of the Blessed Virgin Mary and made by goldsmith Adrien Vachette.

According to an account written by Catherine Labouré, Mary was clothed in a robe of auroral light and her robe had a high neck and plain sleeves. According to Catherine's notes, the medal should also have half a globe upon which Mary's feet rest, hands raised up to her waist, fingers filled with diamond rings of different sizes giving off rays of light, and a frame slightly oval with golden letters saying, "O Mary! conceived without sin, pray for us who have recourse to thee!" Her fingers each had three rings and the largest stones emitted the most brilliant rays. She added that some of the diamonds did not give off rays.