When you think of where to buy your engagement ring, you might think of Zales, Tiffany & Co., or Blue Nile. But if you've ever walked past the diamond counters at a Costco warehouse, you might be ...

Tiffany has beaten Costco to the tune of at least $19.4 million in the trademark infringement battle over alleged knock-off rings that pitted the luxury jeweler against the membership warehouse giant.

Tiffany & Co. and Costco Wholesale Corp. have finally reached a settlement agreement over the jewelry store's eight-year lawsuit accusing Costco of trademark infringement and counterfeiting for ...

Did you know you can buy diamond rings at Costco? And expensive ones, at that. The warehouse retailer said during its latest quarter ended May 12 it got a sales boost thanks to a customer purchasing ...

NEW YORK (AP) — A Tiffany & Co. subsidiary is suing Costco, claiming the wholesale club operator has been selling engagement rings wrongly labeled “Tiffany” rings. The high-end jeweler filed lawsuit ...