Syna. Baubles Big Diamond & Chalcedony Earrings. The beauty of each Syna piece is its striking simplicity. These versatile 18k gold chalcedony Syna earringsdetailed with diamondswill take you from the beach, to brunch, to the ballet. From the Syna Baubles Collection. 18-karat yellow gold. Champagne pave diamond dome, 6mm. Polished chalcedony cabochon drop, 12mm. Chalcedony, 15.0 total carat weight. Diamonds, 0.50 total carat weight. Post backs. 7/8"L overall.