Blue stone necklace/brooch rose gold toned chain

I have had this necklace/brooch combination for many years. It is not marked. The stones are blue and the chain is rose gold toned. The clasp is like a c-ring clasp, only it does not have the little knob that most c ring clasps have, I first thought it was broke, but that is the way it is made. It looks like it could be an art deco piece due to the lines and circles of the piece and the 4 chain links that hang down from the necklace. I love this piece, anyone have any idea who the maker might have been.