18K: Gold with a purity of not less than 750‰.
24K: theoretical purity is 1000‰ (actually not less than 996‰).
22K: Gold with a purity of not less than 9 16‰.
Pure gold: gold with a purity of not less than 990‰.
According to GB11887-2012, the regulations and naming methods of precious metals in jewelry:
Thousands of pure gold: gold with a purity of 999‰ (the term "thousands of pure gold" was abolished on May 4, 20 16).
Tiger Gold: Gold with a purity of 999.9‰. The imprint is "Wanjinjin", "999.9 Gold", "au999.9" or "G999.9". There is no title of "tiger balm" in the national standard.
Gold bars used for investment are generally thousands of gold, and gold bars used for handicrafts are generally thousands of gold.
Extended data
Identification method of gold jewelry;
1. According to the different luster and color of gold, pure gold, k gold, real gold and fake gold can be roughly distinguished.
2. The density of gold is 19.32g/cm3, which is about twice as heavy as that of silver, lead and tin with the same volume.
3. Gold has the characteristics of ductility and low hardness, and can be pressed into thin sheets with a thickness of 12.7 microns. When the color is high, you can scratch it with a pin or nail to leave traces.
4. When the high-quality gold jewelry is knocked or thrown to the hard ground, it makes a dull and low sound of "poof-poof-poof-poof", which has no rhyme and elasticity. K gold has rhyme, sound and elasticity. The greater the elasticity, the older the rhyme and the worse the color.
5. Use gold to grind the card and the tested jewelry on the touchstone, and judge the fineness of gold jewelry through color comparison. The method should be carried out under natural light and fluorescent lamps, not under direct sunlight and incandescent lamps.
6. Polish the gold trace of the identified jewelry and brand on the touchstone, and try nitric acid on the gold trace with a glass rod. Because the chemical property of gold element is stable and does not react with acid, its color remains unchanged.
The purchase method of gold ornaments is as follows:
1. Have a formal tax invoice, name, color and weight of jewelry.
2. Choose according to everyone's age, temperament, body shape and purchasing motivation.
3. Carefully check whether the jewelry has burrs, whether the chain is straight, and whether the buckles, connectors and ear clips are safe.
Jewelry sometimes turns white when worn. This is because when jewelry comes into contact with cosmetics, shampoo, detergent or mousse, chemical reactions will occur, so it should also be less in contact with cosmetics when worn. Once it happens, you can ask the store to solve it with the invoice. When storing jewelry at ordinary times, it is best to pack each piece of jewelry separately with soft cloth to avoid losses caused by mutual friction.
Baidu encyclopedia-gold jewelry
Baidu encyclopedia-gold