- 1). Check the box, if the ring came with a box. Cartier used specially branded boxes for all its jewelry and watches and if the piece has its original box, you know that it's a real ring. Most dealers offering reproductions omit the box or give you a generic box. In some cases, the box has Cartier on it, but the poor quality is a tip off that it's not authentic.
- 2). Compare the ring against pictures on the Cartier website. Cartier lists photographs of newer pieces on its site, which lets you compare your ring against modern day pieces. The style of the piece and the metal used, should be similar.
- 3). Look for auctions taking place that offer Cartier rings and jewelry. Sometimes the easiest way to compare your ring to others is by seeing authentic rings in person. Check the markings inside the ring, as well as the style and tool markings on the ring and compare those to yours.
- 4). Read any writing found inside the ring and look for spelling errors. Reproduction pieces are sometimes made in foreign countries, where words are spelled differently or misspelled completely. If you notice that your ring has letters missing or extra letters, it's probably a fake.
- 5). Examine the inside of the ring, looking for a mark that indicates the maker or the carats. Cartier ring makers often signed the inside of the ring by listing a design or logo. Also, look for a copyright date or manufacturing date, which indicates when the piece was made.