Cathy Waterman Cognac Diamond Ring 0 By ExoticExcess on April 2, 2009 Jewelry & Timepieces The Cathy Waterman Cognac Diamond Ring is beautiful. 22k hammered yellow gold and platinum ring set with 1ct cognac diamond and white pave diamonds. The cognac diamond is so unusual, but very chic. Available at Barneys. $3,390 Share. Twitter Facebook Pinterest LinkedIn Tumblr Email