There are five nines in gold, that is, high purity gold, with a gold content of about 99.999%. Because the purity of high-purity gold has exceeded the highest international gold purity standard, its color is reddish gold, which has excellent ductility and malleability, very high thermal conductivity and electrical conductivity, and its properties are very stable.

There are five nines in gold and five nines in gold, which is called high pure gold, and its gold content is about 99.999%. Because the purity of high-purity gold has exceeded the highest international standard of gold purity, the texture is purer, and in terms of color, high-purity gold is naturally reddish gold.

High purity gold has excellent ductility and malleability, very high thermal conductivity and electrical conductivity, and its properties in air and water are very stable. Even at low or high temperature, it will not be oxidized, insoluble in acid and alkali, but only soluble in aqua regia, sodium cyanide and potassium cyanide solution.

Although the purity of high-purity gold is extremely high, the texture is extremely soft, so high-purity gold is mainly used for gold wire bonding in semiconductor devices and large-scale integrated circuits, as well as targets, or high-purity gold-based alloys, and will not be used in the field of jewelry design.