A few years ago, I thought I was developing an allergy to silver and gold. Almost overnight, my skin was turning black underneath my rings and I couldn't explain it. The answer? Science!
At about the same time that my skin started turning colors, I had started using a mineral sunscreen* containing zinc oxide. Zinc Oxide, in its non-nano state, is a fantastic and safe sun-blocking agent as well as a common ingredient in many cosmetics. I am pretty obsessed with my skin care (though you wouldn't believe it if you saw my hands. Ah well, such is the jeweler's life). Zinc oxide is also, as it turns out, a very mild abrasive. Veeeery mild. But gold and silver are soft metals, so the mild abrasive in my sunscreen was actually rubbing off minuscule particles of metal from my rings and these particles transferred to my skin and appeared black.
My solution? Well, I wasn't going to discontinue using my sunscreen nor would I stop wearing rings and the problem goes away when I, you know, wash. My. Hands. I also wait to put on rings until after I've applied the sunscreen and washed my hands. Sometimes the simple solutions are the best.
* I’d like to give a quick shout out to the makers of my mineral sunscreen. Marie Veronique Organics. They care about the safety of their products above and beyond their industry standards and their sunscreens are amazing! It is also a woman-owned and Bay Area-based business.