EthereumEliteGuard
Mon Nov 25 2024
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6 answers
1459
Do gold coins turn black?
I have some gold coins that I've kept for a while, and recently I noticed that they seem to have turned black. I'm wondering if this is a common occurrence for gold coins, or if there's something wrong with them. Do gold coins normally turn black over time?
Andrea
Mon Nov 25 2024
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6 answers
1751
Why do coins turn black?
Coins often turn black due to the formation of copper sulfide, which occurs when copper reacts with hydrogen sulfide or solutions containing it, especially in moist environments. This chemical reaction can be accelerated by perspiration, as it contains sulfur-containing molecules that can break down to form hydrogen sulfide.
