a
The gold state is recognized.
a
Gold is called high purity gold, which means that the purity reaches
99.999%
Gold articles, marked
AU99999
. High purity gold is better than ten thousand gold
AU9999
Higher purity, redder, purer. However, such gold is generally used as reagent gold and will not be used as jewelry gold.
Five of the nine gold countries are recognized.
State documents stipulate only the degree of gold jewelry purity naming, as long as the gold content is greater than 99% of the gold jewelry need to be marked with the word gold. But it does not restrict companies from producing more pure gold jewelry. The five nine gold is called high pure gold, which refers to gold products with a purity of 99.999% and is labeled AU99999.
The production of such high purity gold can be combined with electrolytic refining method and zone melting method, the higher the purity requires more advanced technology, and the production process is more difficult. Such high-purity gold is mainly used for semiconductor devices, bonding gold wires in large-scale integrated circuits, and high-purity gold-based alloys, etc., and will not be used as jewelry gold.