The opal itself is approx. 8.8mm x 10.8mm. The shank in back is approx 2.2mm wide. This ring is in pre-owned condition, but remains in excellent condition. The opal is fiery & full of life!I think you will love it!! Opal is the October birthstone. The item "Vtg Estate natural OPAL oval ring 18k yellow gold simple art deco 9x11 opal" is in sale since Wednesday, April 8, 2020. This item is in the category "Jewelry & Watches\Fine Jewelry\Rings". The seller is "thelongs1" and is located in Barrington, Illinois. This item can be shipped to United States.