B in a circle

What is the item? Diamond bracelet, looks to be about a carat to 1.5 carats

Can you please provide all background information?
Bought on eBay as 10k solid gold

What are the markings?
the clasp is marked 10k but the bracelet seems a little iffy, and the only marking on the bracelet is the letter B inside a circle


Where are the markings?