http://www.copyright.gov/circs/circ40.pdf
...ummm...This document from the US Copy Right Office seems to say that jewelry designs can be copyrighted...
I know a patent attorney...I'll ask him if he has any insight on copyrights the next time I see him. I recently saw him and his wife and he was telling me that the laws regarding art work are different in Europe than in the US. My nephew is going to have a show in Copenhagen...and as we were chatting about it he [the lawyer] mentioned that in Europe the artist has some control over how their art is displayed even after it is sold...I had no idea that was true.