The Duchess of Cambridge, Kate Middleton, continues to impart her magical effect on fashion -- this time on her one-of-a-kind engagement ring! (Who knew that was possible?) The diamond and sapphire ring previously worn by Princess Diana was famous when William's mother wore it, and it now tops the list of the most iconic rings ever worn.

The ring, first purchased in 1981 for £28,000 (about $60,000 then), is now worth over 10 times that figure at £300,000. The popularity of sapphires skyrocketed when both women received the ring and the amount of replicas out there is a little out of control.

With 14 diamonds surrounding a 12-carat oval sapphire, this ring was always going to be a show-stopper. And while Duchess Kate looks down at her hand and sees the ring as priceless, the actual value is growing every day.

William reportedly had to take the ring out of the royal vault in a "cloak and dagger" operation, carrying it around in his backpack for three weeks before proposing to Kate while they were on vacation in Africa. When Diana passed, the ring initially went to Harry (and William got a Cartier watch), but the younger Prince decided that it should sit on the hand of the future Queen of England, so he gave it to his brother for Kate.

Click through the gallery above to see the best photos of Kate's stunning sapphire ring.