IIRC, we concluded that they all wore the necklace as a tiara. Although JC wore the Congo necklace together with the Belgian scroll tiara at her church wedding, she changed to a simple diamond riviere necklace and the Congo necklace on a tiara frame for the official wedding pics.
I think that I posted this comparison before. It shows that the wedding tiara has three rows of diamonds, like the necklace. The Congo bracelet only has two rows of diamonds. free photo upload