Stuller, A. Lange & Soehne and Jacob & Co.
What about the rest of the regal bling? We asked style expert Michael O'Connor to give us his take on the kind of sparkly accessories the prince and princess may be wearing on the big day and beyond:
Kate's Wedding Jewelry
Kate loves fashion and has a tailored and sophisticated style. She won't want to be seen as the "fairy-tale princess bride." I think her style choices will be much more youthful and simple, but with some dramatic elements. Classic diamond stud earrings and a Riviera-style necklace will probably be her first choice of wedding jewelry.
Her gown is rumored to be made by Sarah Burton, who gave us fitted tops (many with collars and cap sleeves) with full skirts and lots of movement in her spring 2011 show. If Kate chooses one of Burton's higher-collared gowns, she will probably switch out the necklace and add a substantial gate-link platinum-and-diamond bracelet to keep a voluminous skirt in proportion. And if Kate does opt for a tiara, we will probably see a simple platinum-and-diamond style with smaller pave diamonds.
Bride's and Groom's Wedding Gifts
As a couple, William and Kate are very romantic, but practical. They'll want to give each other jewelry pieces that can be worn often. Kate's gift to William will most likely be something elegant, but useful, like a pair of platinum cuff links -- perhaps engraved with their initials or a meaningful mark. William's gift to Kate will have the same romantic sentiment, maybe platinum-and-diamond stud earrings to be worn on their wedding day.