Men's 18K Yellow Gold Hardwood and Maple Burl Wood Satin Finish 6mm Wedding Ring. Lightweight and unique, this mixed material ring features a precious metal satin finish exterior and a maple burl hardwood interior that's coated in a protective resin. Burl is a rare and prized pattern of tight swirls in maple wood that varies in color from honey to medium brown. To properly care for a hardwood ring, read our Jewelry Care Guide.