From Jennifer Lopez's pink engagement ring to Kim Kardashian's 15-carat stunner, read on for a roundup of some of the most expensive celebrity rings of all time.

But Ajay Anand, CEO of Rare Carat, believes the ring could be worth even more. “Our team of gemologists and diamond PhD’s estimate the emerald-cut diamond is 20 carats and worth around $4.5 mi ...