Koa wood (acacia koa) is found in Hawaii. The color can be highly variable, but tends to be medium golden or red/brown (similar to mahogany). The grain of koa wood is usually slightly interlocked, and sometimes wavy. Tungsten is a an extremely hard and dense metal. When combined with carbon alloy, it transforms into tungsten carbide. It is this durable tungsten carbide we use to craft our rings. As tungsten is so hard, so it is very difficult for a tungsten ring to get scratched (making it scratch resistant). This beautiful ring is crafted from black tungsten carbide, and features two wood grain inlays and polished stepped edges. It is then finished with a natural resin coat. Our rings are lead free. Band options: 8 mm note: bands cannot be resized after purchase.