A: As one of my more astute colleagues pointed out (because it didn't occur to me), nickel is a metal, not a mineral. And mineral makeup does not usually contain metals. But there is a reason you might want to be careful, says Ellen Marmur, MD, chief of the division of dermatologic and cosmetic surgery at Mount Sinai Medical Center in New York City. Mineral makeup, especially if it's blue, may contain cobalt, which is found in the soil (where minerals come from) and can cause a reaction similar to that of a nickel allergy.
Bottom line: If you can live without blue eyeshadow, you shouldn't have a problem.