Mikimoto pearls with diamonds in the blue velvet box. Please see card for more details. 18k white gold posts. 6 x 6.5mm Please note*** I swapped out the backs on these for a new pair. They were brittle, and I didn’t want to risk someone losing one of these. I also was made aware these are not the original backings. This is exactly how they were gifted to me, so this is the best I can do. 🤷🏻‍♀️