Tiffany & Co 1837 Interlocking Circles 16” Necklace AG 925. Dainty rolo chain. Spring ring clasp. Clasp is marked “925”, the tag by the clasp says “Tiffany&Co” on one side and “AG 925” on the other. Both rings are a little over 1/2 an inch in diameter and marked “925 T & Co 1837”. I did test the metal to verify it was indeed sterling silver. It could probably use a better cleaning/polishing, but otherwise in great condition.