Congrats! You did the right thing!
From what I understand most modern diamonds are laser etched with a serial number which is in a database, when the ring is lost or stolen the number is reported, and when someone sells a big diamond ring to a reputable dealer, it must be checked for a serial number on the stone and ran to see if it comes up lost or stolen. Just like a car VIN#.
Not sure when they started doing this, but it makes it hard to sell those really nice diamond rings.