VTG AB Rhinestone Brooch Pin Smoky Topaz Blue Layered Prong Set Fillagree Round

Vintage AB Rhinestone Brooch Pin Smoky Topaz Blue Layered Prong Set Fillagree Round Stunning Aurora Borealis (AB) Rhinestone Layered Brooch  Prong set with smoky topaz navette rhinestones and blue AB round rhinestones with filigree metalwork  Layered Design Silver tone metal  Measurements pictured  Good Used Condition- All stones are present. One of the navettes is more green than the others. I am not sure if it has changed color over time or if it is a replacement stone (see pictures)