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Name: Giselle
Status: other
Country: United Kingdom
Date: Summer 2009

I would like to know if gold would decompose in salt water and what the state of a gold necklace submerged in salt water be like after 20 years. Would the gold necklace be intact or would decomposition of the metal have occurred? If so, what would be the state of it?

Assuming you are talking about pure gold (not low-carat), the gold itself is not going to substantially degrade. Gold does not readily oxidize, which is one of the reasons it has been used as money. In the ocean, many things might stick to it though, and cause it to be covered. Because gold is so soft, it is not easy to clean (without damage) once things like barnacles are stuck to it.

Hope this helps,
Burr Zimmerman

Hi Giselle,

Gold will not "decompose" in salt water. In fact, salt (or sea) water will not affect gold in any way, no matter how long the gold is exposed to it. Not only is gold unaffected by salt water, it is also totally unaffected by most strong acids. The only thing that will attack gold at normal temperatures is "Aqua Regia", which is mixture of 1 part concentrated nitric acid, to 3 parts concentrated hydrochloric acid. Gold will slowly dissolve in this mixture, but is unaffected by just pure nitric acid or pure hydrochloric acid (or any other common acid).

So to answer your specific question, your gold necklace after 20 years exposure to salt water would look like new. This assumes pure gold, and not an alloy.

Bob Wilson

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