Mary-Kate and French banker Oliver Sarkozy have recently decided to tie the knot. Olsen has been spotted wearing a vintage Cartier engagement ring form 1953. The ring originally belonged to a Tennessee-based jewelry collector and was bought by Sotheby’s famous auction in New York City. The center European-cut diamond is 4 carats and framed by 16 sapphires, surrounded by single cut diamonds petals. This ring is a fitting choice for this fashoinista, considering her affinity of unique vintage attire. The big question is, did Mary-Kate break tradition and buy the ring herself? Regardless, the ring is a perfect match for her. We congratulate this couple on their engagement and look forward to the wedding photos!