Gold jewelry refers to jewelry made primarily from gold

Gold jewelry refers to jewelry made primarily from gold. The chemical symbol for gold is Au, with a specific gravity of 17.4 and a Mohs hardness of 2.5. Gold jewelry can be divided into two categories based on its gold content: pure gold and K gold.
The gold content of pure gold jewelry is over 99%, with a maximum of 99.99%, hence it is also known as "Nine Nine Gold", "Ten Foot Gold", and "Red Gold". In order to overcome the disadvantages of high gold price, low hardness, single color, easy wear and tear, and delicate patterns, other metal elements are usually added to pure gold to increase the hardness of the jewelry gold, change its color tone, and lower its melting point. This results in gold alloy jewelry with different fineness and gold content, which is named "Karat". The K gold system is an internationally popular gold measurement standard, and the complete representation of K gold is "Karat Gold", which gives K gold an accurate gold content standard, thus forming a series of K gold jewelry.