If the photographs were produced as work-for-hire for the supplier, then the supplier owns the copyright. If not, the photographer owns the copyright. Either way, you can't use the photos without permission.
You own the copyright of your original jewelry designs, so if these pieces are the central focus of a photo, then use of that photo may violate your copyright.
In short, neither of you has rights to use the photos without the permission of the other.
(However, if each of your previously allowed the other to use the photos, there may be some implied contract issues here.)
The real question is, what do you want to get out of this? If you expect the supplier to destroy all their brochures and catalogs, I'd expect a fight... one which you may win, but will be expensive for both of you. You might consider trying to work out an arrangement where each of you can continue to use the images for some fixed period of time.
If you want the images of your jewelry off the supplier's website, you can probably accomplish that by filing a DCMA takedown request... it's free, it's easy, and in almost all cases the website hosting company complies. But of course, the supplier can do the same to you.