Nb is also hypoallergenic and extremely corrosion resistant. Colors are much more vibrant than titanium but are difficult to accurately reproduce using photographic methods for printing and/or computer display. We have done our best to show accurate representations of our colors but the differences between computer monitors and printers make this task difficult at best.
Nb is one of several ‘reactive’ metals which are anodized using electricity with no dyes or pigments. Voltage creates varying thickness oxide layers which produce colors by interference. These oxide layers range from 50 millionths of a millimeter to 100 millionths of a millimeter in thickness. Light is reflected from the oxide surface and from the metal surface slightly delayed. It is the interference between these two reflections that either cancel a color wavelength or enhance a color wavelength of light. The thickness of the clear oxide layer determines the interference wavelength / color. It is this interference that also allows the color to vary dependent upon the viewing angle. This color shift is more pronounced for some colors i.e.: blueberry (blue-purple) and rhubarb (pink/green). By the way, our rhubarb color has yet to be duplicated by any other niobium ring supplier. As the name suggests, the color shifts from pink to pale green depending upon the angle of the ambient light and viewing angle.
Anodizing niobium is NOT an exacting science. There are many variables which prevent results from being repeated by using an exact recipe.
Information has been reproduced with the permission of chainweavers.com (our suppliers)