It never hurts to ask! The Catrin Gem Ring was born when a client asked if Rob could add a gem to the Catrin Knot Ring. He liked the result and decided to put it into production. The Catrin Gem Ring has a 6mm cabochon at the center of the knot. It measures about 1/2 inch at the top and narrows to just over 1/8 inch at the back.