Whether it is five nines or four nines, it refers to the purity of gold. In other words, the gold purity of four nines reached 99.99%, while the gold purity of five nines reached 99.999%. As far as the line is concerned, the gold purity of five nines is higher, that is, ten thousand gold is often said, and four nines are also called thousands of gold. Because the gold jewelry of five nines is more pure, the fineness will be higher.

Gold is a metal element with low hardness, so the higher the purity, the softer it will be. If more alloy components are added, the standard of hardness will be higher, so five nines of gold will be softer than four nines of gold. If it is accessories, such as bracelets and necklaces, it is recommended to choose 49 gold, which is not easy to deform when worn.

Four "points for attention" in buying gold

As far as color is concerned, red and yellow are the best.

Second, according to the density, 19.32g/cm3 is pure gold or relatively pure gold.

Third, look at the hardness. High-quality gold can be marked with nails.

Fourth, look at the degree of bending. The higher the fineness, the softer the gold jewelry will be, and wrinkles will appear when it is bent, while more impurities will easily break.