Anne Koplik Jewelry - Beautiful Chalcydony Blue Open Heart Necklace with Crystals. Beset with lovely aqua blue opalescent crystal stones reminiscent of Chalcydony quartz crystal. The metal has a bronze patina finish to give a softer more traditional look. Bronze finish is electroplated over brass without using nickel. Fastens with a solid lobster claw clasp. Trademark Anne Koplik Designs. Made in the USA.