Irene Neuwirth One-of-a-Kind ring crafted of 18k rose gold bezel-set with a 3.11 ct cognac tourmaline. 3.11 ct cognac tourmaline. Satin-finished 18k rose gold. 4mm band width, 11mm face width (approximately). For information about additional ring sizes, please contact our customer service representatives via email at webservices@barneys.com or by phone at 888.222.7639.