Nice Brighton reversible heart necklace, one side is plain and the other side has 3 crystals at the end of each swirl. Necklace has a lobster claw fastener with the Brighton heart charm attached..I am not sure of the type of chain but it could be a foxtail or braided chain...it is a nice round sturdy chain...approximate length of the chain is about 16" and there is an additional couple of inches to allow for lengthening. Comes with Brighton bag.
Silver in color and according to research: 

 Brighton jewelry is made using a blend of different metals, notably brass and zinc, which is coated in silver plating.