Jewelry Showcase Factory: Why does gold turn white, black or fade?
Gold symbolizes wealth, and gold jewelry is favored by Chinese people because of its beautiful implication. However, many consumers find that gold jewelry will turn white after wearing for a period of time, resulting in doubts about the fineness and authenticity of gold. So why does gold turn white?
Why Gold turns White ?
There are more and more cosmetics and cosmetics that people come into contact with nowadays, and many unknown factors may cause the discoloration of gold, such as gold and silver jewelry worn by medical workers, which is most likely to be discolored by the surrounding environment.
Trace amounts of lead in cosmetics react with gold to whiten.
In addition, some people wear gold rings and platinum rings on the two adjacent fingers of the same hand. Because the fingers need to move frequently, it is easy to cause friction between the two rings, resulting in partial whitening of gold jewelry.
Why does gold fade?
The fading of gold jewelry is closely related to human sweat. 99% of human sweat is water, and about 1% of human sweat is waste and harmful substances, such as chloride, lactic acid, urea and ammonia.
Any metal exposed in the air will react with oxygen in the air. The final result is a layer of oxide formed on the metal surface. If it is found that there is a change in the gloss of gold jewelry when it is bought, it is actually caused by the long-lasting oxidation reaction, which is called “rusting”.
The rusting of gold is not obvious because of its strong anaerobic property. Gold ranks last in the list of metal activities. Gold can therefore maintain a long-term bright color, which is also one of the reasons why people use gold as jewelry materials.
Why Gold gets Darkens ?
When silver and copper in gold jewelry come into contact, chemical reactions will occur, resulting in silver chloride and copper sulfide, and showing dark black chemical salts. This chemical often falls from gold jewelry, contaminating the wearer’s skin, leaving a very clear black stain on the skin.