Hypoallergenic applications of niobium: medicine and jewellery
Niobium and some niobium alloys are physiologically inert and thus hypoallergenic. For this reason, niobium is found in many medical devices such as pacemakers. Niobium treated with sodium hydroxide forms a porous layer that aids osseointegration.
Along with titanium, tantalum, and aluminium, niobium can also be electrically heated and anodized, resulting in a wide array of colours using a process known as reactive metal anodizing which is useful in making jewelry. The fact that niobium is hypoallergenic also benefits its use in jewelry.