Blue goldstone was first created in Venice, Italy, in the 16th century. It is one of the first man-made jewelry materials to be created. It gets its blue from cobalt powder, and its sparkle from copper powder, in glass! So, while not a stone at all, it is undoubtedly beautiful. On antiqued brass bar chain, with a vintage parrot clasp and vintage bail, these are the narrowest of the blue goldstones I currently have in stock, but are about the same length as the largest ones.