u/EasyDevelopment6242

I found this in some of my mother's costume jewelery and I think it maybe real. The clasp is printed with '585' and one ine side of the chain it says '585 ITALY' and the other side says 'Dep. Int. B.C.'. All of the info I was able to find about Italian hallmarks says there should be a star and numbers to show who made it, but these are the only marks I found. Any ideas on when it may have been made and by whom? Thanks for any info!