Why does the surface of gold jewelry turn from white to black

After wearing gold jewelry for a period of time, especially in summer, there will be fading and discoloration. Many people think that there is a problem with the gold they bought, or it is caused by insufficient fineness, so they go to negotiate with the seller. In fact, this is caused by the reaction of chemicals in the air with impurities in gold. Why does the surface of gold jewelry turn from white to black? After wearing gold jewelry for a period of time, especially in summer, there will be fading and discoloration. Many people think that there is a problem with the gold they bought, or it is caused by insufficient fineness, so they go to negotiate with the seller. In fact, this is caused by the reaction of chemicals in the air with impurities in gold. Why does the surface of gold jewelry turn from white to black? Gold jewelry contains gold. When gold encounters mercury, it will react with each other to form a'gold amalgam', that is,'gold mercury contains gold', and the color is white. There are many types and brands of cosmetics nowadays. Some cosmetics contain trace amounts of mercury. When using cosmetics, if you accidentally touch gold jewelry, the place will turn white and produce'gold mercury containing gold'. Similar to this principle, some cosmetics or hair dyeing The agent contains a small amount of lead, and the gold will turn black when it meets the lead. For the above two kinds of gold jewelry that have turned white and black, they can be heated with the gasoline jet wheel used for jewelry processing. Because the melting point of mercury and lead is very low, they will volatilize during the heat treatment of the jet wheel and restore the original gold jewelry. face. Of course, it is best not to wear gold jewelry when applying makeup or dyeing hair to avoid future troubles. The partial blackening of the gold necklace is mainly at the junction of the ring and the ring. Because the ring and the ring side of the necklace need to be welded, welding is required during welding. The grades of the solders used by various manufacturers are not necessarily the same. Some solders contain low gold content. Such necklaces will sweat after a period of use, especially in summer. After soaking, black will appear. Some people who trade in the old said that the necklace I gave them was golden yellow, and there were many small black spots when I returned it to me. It was burned with a gasoline jet when the old was traded in, and the stone appeared black where it was pure gold. This coincides with the saying that 'real gold is not afraid of fireWhy does the surface of gold jewelry turn from white to black? It is best to regularly send gold jewelry to the jewelry store for inspection, cleaning and polishing, because the surface dirt needs to be sent to the jewelry store for professional cleaning, so that our gold jewelry can restore its original luster. Previous: How to clean platinum necklaces Next: How to clean platinum necklaces at home