Cartier 3 diamond ring is written on the inside of the Cartier 750 and then a C, a diamond -shaped after a circle in a circle

Your Cartier ring is a LOVE ring. According to my experience, the Cartier ring is depending on the width and narrowness, and the top layer of the inside reads Cartier. Size; the lower layer is the product coding, both of which are the first two digits, the latter four are numbers, and the diamond logo is next to it. Web links
It, Cartier is a global guarantee. If your Cartier is genuine, you can enjoy warranty and once a year in any specialty store in the world. Therefore, you can go to the specialty store with your ring. If it is not genuine, they will not be maintained for you, and you will not have any losses. By the way, you will notice it.