FOR YOUR CONSIDERATION IS THIS STUNNING STATEMENT RINGTHE STONE IS VERY CONFUSING. I SENT IT AWAY TO BE PROFESSIONALLY TESTED. IT CAME BACK AS SYNTHETIC COLOUR CHANGE SAPPHIRE TRYING TO LOOK LIKE ALEXANDRITE! A VERY EARLY RING FOR THIS TYPE OF STONE & THEY DID NOT THINK IT WAS A REPLACEMENTTHE HEAD MEASURES 25 X 11MM APPROX, SO, VERY NOTICEABLEBEAUTIFULLY CUT. BOTH JEWELLERS SAID WHAT A BEAUTIFULLY HAND MADE RING THIS IS & ESTIMATED FROM THE 40'S / 50'SSHOWS LOVELY COLOURS... FROM DEEP AMETHYST TO SWISS BLUE TOPAZ COLOURWAYSMEASURES A SIZE M 1/2PLENTY OF GOLD IF YOU NEED IT RESIZED