Sterling silver, 22K gold, Australian Bould opal. This opal is amazing, within the ironstone matrix are beautiful blues, green and purples. The unique "U" shape of the band, hugs the finger to keep the ring from flipping from side to side. The ring sits up from the finger slightly hence the name "Stand Up". WILL FIT SIZES 8.5 TO 9. PLEASE LOOK AT ALL THE VIEWS TO SEE THE SCALE. EXCHANGES ALLOWED WITHIN 10 DAYS OF RECEIPT.