Color discrimination method. Gold is "seven greens, eight yellows and ten reds in nine purple". It means that the blue one contains 70% gold, the yellow one contains 80% gold, the purple one contains 90% gold and the red one contains almost 100% gold.
2. Speech recognition method. Let the jewelry fall to a hard place, and the sound is dull, indicating that the color is good; The sound is crisp, indicating color difference.
3. Bending identification method. Hand-bent jewelry is soft in real gold, easy to bend but not easy to break, while fake or gold-plated jewelry is generally easy to break but not easy to bend.
4. Trace identification method. Scraping the real gold surface with a hard needle tip will have obvious marks, while the fake marks will be blurred.
5. Weight identification method. Gold has the largest specific gravity among known substances, with a specific gravity of 19: 37. The volume of brass and copper with the same weight is much larger than that of gold and red gold with the same weight. Look at the color and weigh it with your hands.
6. Fire identification method. Real gold jewelry can not change color for a long time, and fake jewelry is not fireproof. It will turn dark brown and lose its luster after burning. Good luck and good luck!
GOLD (English gold), commonly known as gold, the symbol of chemical elements is Au, and the code name of gold is a kind of metal with yellow luster. Gold has good physical properties, stable chemical properties, high ductility and rare quantity. It is not only a special currency for reserve and investment, but also an important material for jewelry industry, electronics industry, modern communication, aerospace industry and other departments. Gold is gold with the chemical symbol Au. Gold is one of the rarest and most precious metals in the world.
Gold is an early metal discovered and utilized by human beings. Because it is rare, special and precious, it has been regarded as the first hardware since ancient times and has the title of "King of Metals".
On 201865438+1October 17, gold futures prices closed higher for the fifth consecutive trading day and hit the highest closing price in four months.