Bulgari jewelry design is distinctive and often imitated (and counterfeited). In the 1970s, many of the more expensive Bulgari pieces (such as necklaces, bracelets and earrings) were characterized by instantly recognizable, bold, architectural designs combining large and weighty gold links with interlocking steel. Bulgari is also famous for colored stones, especially sapphires mixed in unique formats. Genuine Bulgari watches have a unique serial number that is registered with the company.