The Duchess of Cambridge debuted Sapphire and Diamond Earrings which are a perfect match for her engagement ring in the summer of 2011 before the North America tour.
The Duchess of Cambridge was first seen wearing those earrings in 2011 for an official portrait clicked at Clarence House before North America Tour. I always thought that the pair belonged to Prince William’s mother Lady Diana, but The Court Jeweller have more information on them that showed that they are actually not.
The Diana earrings feature two sapphires, the top sapphire is surrounded by eight diamonds, and the bottom by nine diamonds with a single diamond between both. It was believed that giving her own touch The Duchess of Cambridge remodeled the stud earrings into dangling. But they turned out to be a completely different set matched by a pendant necklace.