Silver Gold

Why does my skin turn black when I eat tomatoes and wear silver/gold?
I don’t wear jewelry much, except for hook earrings and necklaces that aren’t any kind of metal. I recently received a silver watch as a gift and I’ve been wearing it a lot, and yesterday I ate tomatoes and now I have a black band on my arm.
My mom gets it too, so I guess it’s genetic. She says it happens with gold, silver, or any kind of metal jewelry.
…What makes my skin turn black? :/
It’s a reaction between the chemicals in your body sweat and the alloys in the jewelry metals. Gold nor silver are actually 100 percent pure, they all contain various other metals to give them strength. As a rule, nickle is one of those metals and it often doesn’t agree with folks’ skin. You can solve the problem cheaply enough with a bottle of clear nail polish. You just use that to paint a coat on the backside of the piece which will come in contact with your skin. That will create a barrier between the two of you, and your skin will not react with the metal. When you notice a bit of discoloration after wearing it, you just re-coat it. With things like earrings, it is best to stick to surgical stainless steel posts and backs- which do not react the same way.
$8000 Gold & $500 Silver, MINIMUM : Chapman Part 1 of 2