These are the types of people with whom jewelry designers often work:
Buyer: Representative of a retail concern who buys product wholesale from a vendor/manufacturer. Jewelry buyers often attend trade shows to look at product.
Marketer: Usually specializing in analyzing the market for a given company and often specifying what jewelry will be created.
Merchandiser: Decides how a product is to be sold: i.e. display, catalogue creation, in some companies creating the line itself.