Nitric acid, magnet and unglazed ceramics were used for identification. Take nitric acid identification as an example. Go to the hospital, chemical industry or gold sales office to find a bottle of nitric acid. Dropping nitric acid on gold is false if it produces green. If it is milky white, it is gold-plated or pure silver. If nitric acid drops without any reaction, then it is true.

999 pure gold means that the purity of gold reaches 99.9%, also known as "thousands of pure gold", which can also be said to be pure gold and 24k gold. This kind of gold ornaments are usually marked with thousands of gold, 999 gold, gold999 or g999. In contrast, the pure gold with higher purity is "Wanjinjin", that is, AU9999 or G9999. Gold has the name of seven greens, eight yellows and nine reds, which shows the fineness of gold.

Gold selection skills

1, depending on the hardness

Pure gold is soft and has low hardness. You can draw shallow marks with your nails and bite out teeth marks with your teeth. Gold ornaments with high fineness are softer than those with low fineness, and the more copper they contain, the harder they are. Bending method can also be used to test hardness. Pure gold is soft and easy to bend, and the lower the purity, the more difficult it is to bend.

Step 2 use fire

Burn the jewelry to be identified with fire, do not melt and deform the jewelry, and observe the color change after cooling. If the surface is still golden, it is pure gold; If the color darkens or turns black to varying degrees, it is not pure gold. Generally, the lower the fineness, the thicker the color, and all of them turn black, indicating that they are fake gold ornaments.