Zirconium is a light and extremely durable metal similar to titanium. One benefit of zirconium is that when heat treated, the surface becomes black and attains a sapphire hardness. The ring in questions has a dazzling brilliant cut diamond which contrasts effectively against the black. Other widths and depths are available and also in a polished finish – the ring imaged is 7mm width by 2.25mm depth and is satin finish. Please call or email for more details.