Vintage White and Blue Screw Back Earrings - Clip

Vintage dangle / drop earrings. Unsure what the center peice is, possibly Bakelite . . .white Center stone has a halo of sparkly light blue rhinestones. So pretty! I wore to a wedding (something blue!) and I have pierced ears and they were really comfortable for being clip/screw back earrings. Non-pierced/ clip-on vintage earring with twist screw closure. In very nice vintage condition. Purchased at an antique store