Just as I suspected! Lurking out there, often not showing up until middle age, is something known as "contact allergic dermatitis", waiting to spoil our delight in wearing jewelry. You would expect this from certain foods, flowers, and pharmaceuticals. But metals? After a quick web search of the topic I learned to spell met-allergy.
It turns out that certain metallic elements are reactive, meaning that some of the electrons in its electron cloud are willing to swap orbits with other free electrons in their vicinity. It is what we call oxidation or tarnishing. The primary culprit is nickel, which is often used to alloy sterling, stainless steel and even some gold-filled metals. Most people never have a problem with this process. Their bodies accept it. But some of our metabolisms try to reject or isolate or defend against the offending electrons. At this point, I already knew more than I wanted or needed to know about the chemistry. What I needed was to find a pure, natural, non-reactive element that is free of things like nickel and lead - and hopefully, something less expensive than platinum! Enter Niobium!
Number 41 on the periodic table, used by Edison as filaments in his electric light bulb, adapted for use by NASA in space vehicles, Niobium has a storied history. It is strong, malleable, and 'half-hard' to shape - like sterling (and unlike pure gold and silver, which are termed 'dead soft'). But what interests us is: hypoallergenic. Also interesting to the jewelry artist is that Niobium can be electrolytically anodized into flashy colors like blue, green, purple and even pink!
|Enamel Earrings on Niobium Ear Wires|