Tiffany & Co. 18k Yellow Gold Sea Urchin Brooch Consign Now DeptJewelrySizeDiameter 1.50 in. 22.31g Tiffany & Co. 18k Yellow Gold Sea Urchin Brooch, marked Tiffany & Co. 18k; 22.31g 14.35dwt Provenance: The Estate of Carole P. Webster, Nantucket Island, Massachusetts Diameter 1.5 in. Please note that this auction has ended. Click here for an overview of this auction.