Antique Necklace?

My passion is Vintage and Antique Jewelry. Needless to say, I buy a lot of it. A few months ago, I bought several jewelry items from a Northeast Coast Estate Jewelry Collection. There were two pieces similar, but different to the pictures I have posted. No signatures nor other identification marks were found on either. The metal looks like brass, but I have no way to test for brass? Some of the stones are Aurora Borealis; however, they could be Carnival Glass, since AB stones came available in the 50's, from what I have read? The markings on the back of the necklace are similar to 1928 markings, but a bit different. There is a small heart hang tag attached to the extender, of which, I am not familiar. With what can be seen, can anyone add further information regarding this beautiful necklace?

I will add the other, as well.