When gold jewelry causes discoloration of skin, it is due to a chemical reaction between the jewelry and oils on the skin. Most gold jewelry is not actually solid gold and can contain different metals, such as copper or ... More »

Goldfish babies, or fry, change from black or dark-gray at birth to a golden color by age one. Environmental factors influence the degree of color they achieve. More »

Real gold does not tarnish. The metal is not susceptible to oxidization, meaning it does not turn brown, black, green or any other color over time. Dark spots or unnatural hues to a piece of gold indicate impurities and ... More »

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Gold in its purest form does not leave black or green marks on skin, but the other metals mixed in with gold jewelry, such as copper, nickel and silver, can cause discoloration on skin. Discoloration usually occurs when ... More »

Sterling silver turns black or tarnishes due to a chemical reaction caused by contact with sulfur or hydrogen. Some foods or everyday items containing sulfur can cause tarnishing, but even polluted air can turn sterling ... More »

Fourteen-karat gold is gold that has been alloyed with equal parts silver and copper in order to provide additional durability and rigidity in jewelry, with the final product containing 58.3 percent gold, by volume. This... More »

Clean tarnish from your pure gold jewelry by immersing the jewelry in warm water with a couple of drops of dish soap and rubbing gently with your fingers or a washcloth. Do not use this method for gold jewelry that incor... More »