Getty A couple who found a pearl inside a clam while on a date ... Get All the Details on Winnie Harlow's 8.5-Carat Oval-Cut Diamond Engagement Ring from Kyle Kuzma — That He Designed!

But what is it that makes pearls so expensive? Marie Antoinette's pearl was part of a diamond-studded pendant, and it has important historical significance, which increased its value. But there ...