Question

Why gold turns black after few years

Answer 1

Jewelry made of pure gold doesn't tarnish because it doesn't corrode or oxidize, but gold pieces made with an alloy such as copper or silver may tarnish and turn black. Gold jewelrycan also darken when it's frequently exposed to soap, lotion and everyday grime.

Answer 2

due to burning of coal sulphur is form abd this karge amount of sulphur makes gold black in few years