The reasons for the blackening of silver ornaments are as follows:

1, which is determined by the nature of silver itself.

The chemical properties of silver are more active. If you encounter hydrogen sulfide gas or sulfur ions in the air, it is easy to generate a substance that is difficult to dissolve-silver salt, and chemical reactions can also occur when you encounter little hydrogen sulfide gas or sulfur ions. Over time, silver salt will form a silver sulfide film on the surface of silver ornaments, which is gray-black, and silver ornaments will gradually become gray-black.

2, caused by human sweating.

When wearing silver ornaments, human sweat contains sulfur, ammonia and so on. Moreover, the air also contains hydrogen sulfide, nitric oxide and other substances, which will lead to the oxidation of the surface of silver ornaments, and then change color and lose luster. The blackening of silver ornaments is also related to the acidity and alkalinity of human sweat, which is acidic, and the blackening speed of silver ornaments will be faster.

3, hydrogen sulfide and other substances contained in the air.

The air will contain hydrogen sulfide, nitric oxide and other substances, which will oxidize the surface of silver ornaments, and then turn black and lose luster.

4. It is related to the silver content of silver ornaments.

There are many kinds of silver ornaments, among which snowflake silver is the best. Silver ornaments with high silver content and good material generally do not turn black.

Extended data:

How to keep silver ornaments from being oxidized;

1. Wipe it clean and put it away.

If you don't wear sterling silver jewelry for a long time, you must wipe it clean with a soft cloth to avoid leaving sweat stains on the jewelry and causing corrosion, and then put it in a sealed bag or packaging box to isolate the air and prevent the silver jewelry from turning yellow and black.

Don't touch these things

Never wear sterling silver jewelry when soaking in hot springs or playing with water at the seaside, and avoid contact with chemical solutions, otherwise chemical reactions will occur to blacken sterling silver jewelry.

Restore bright colors

You can gently brush it with a soft toothbrush dipped in a little toothpaste, then let the foam adhere to the silver jewelry for about one minute, then rinse it with clear water and dry it with a soft cloth, and you will find that the silver jewelry is bright again.

4. Try not to wash water with silver.

Try not to use silver washing water to clean sterling silver ornaments, because it will corrode the surface of sterling silver. Although it will soon restore its brightness, it will soon turn yellow and black. Moreover, every time the silver washing water is used, it will corrode the silver ornaments again, and the use of silver rubbing cloth will prolong the bright time of the silver ornaments.

References:

Baidu encyclopedia-silver ornaments

People's Network-Why do some people turn black when wearing silver ornaments?