I bought a China gold necklace. Gold weighs 7.82 grams, and the label on it says edit GP 1205030390 and send it to 106289828.

When we get gold jewelry, we first look at the color of gold jewelry. Generally speaking, the higher the purity of gold jewelry, the darker the color.

So how to judge the purity of gold from color? According to industry insiders, the fineness of deep red yellow is above 95%, light red yellow is 90-95%, light yellow is 80-85%, cyan yellow is 65-70%, cyan white is only 50-60%, and yellow white is less than 50%. The so-called seven greens, eight yellows and nine reds can be used for reference.

If we are not very confident in color judgment, we can judge real gold and fake gold (low purity) from the balance weight of gold. According to related metal knowledge, the specific gravity of gold is 19.32, which is heavier than silver, copper, lead, zinc, aluminum and other metals. Because the volume of gold is more than 40% heavier than that of silver, 1.2 times heavier than that of copper and 6. 1 times heavier than that of aluminum. Arabs who often see some gold transactions in movies will throw gold bars in order to judge the weight of gold and further identify the authenticity of gold.

I believe everyone will also see the scene of a domestic movie in which a greedy man bites his mouth with gold. This is of course a way to identify the value of gold. Pure gold is soft in texture and low in hardness. You can draw shallow marks with your nails, and you can leave tooth marks when you bite it. 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 less easy it is to bend.

Here, I would like to remind you warmly that when buying gold jewelry, you should read the above signs clearly, such as "24K" means "full red" or "pure gold"; 18K gold, marked with the words "18K". If the color is lower than Locke, the K-gold seal number cannot be printed according to regulations. This is a common method, but it also has some disadvantages. At present, criminals often make fake brands and imitate stamps, and pass off rare gold, inferior gold and even brass as real gold. Therefore, the identification of gold ornaments should be based on the comprehensive judgment of samples to determine the authenticity and color.

The following may not be suitable for novices to identify the purity and authenticity of gold, but it is still a brief introduction.

The first way is to listen to the sound. Real gold with purity above 99% will beep when thrown on hard ground, which has no rhythm and elasticity. Fake or low-quality gold sounds crisp and dull, generally making a "Dangdang" sound, with a lingering sound, and violently beating after landing.

The second method is to burn the jewelry to be identified (don't make it melt and deform), 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.