William and Kate, for their part, are in “a renewed honeymoon phase reflective of their deepening connection,” Matta said. As she leans deeper into her Princess of Wales role—and is closer every day to one day becoming Queen—“Kate will focus on causes that interest her rather than too many general things,” Vickers said.

Maxwell Stone of Steven Stone Jewelers said that due to its incredible history, the sapphire and diamond pin—which contains a center stone of "at least 40 carats" would be "worth around £8 million" (roughly $10 million) if it sold today.