With the same volume of silver, lead and tin, the weight of gold is about twice. Real gold feels like a pendant in your hand, and fake gold jewelry with high fineness will only make a dull and low sound of "poof-poof-poof-poof" when it is knocked or thrown on the hard ground. K gold has rhyme, sound and elasticity. The greater the elasticity, the sharper the rhyme, and the worse the color. Fake or low-quality gold sounds crisp and dull, generally making a "Dangdang" sound, with a lingering sound, and violently beating after landing. I don't feel like I fell.
When high-quality gold is carved with pins or nails, it will leave traces. More than 97% of colored gold jewelry is folded two or three times, and wrinkles appear at the bend, also known as fish scales; Fake leaves no traces and scales. On the touchstone, grind the gold channel of the identified jewelry and the correct brand respectively, and test nitric acid on the gold channel with a glass rod. Because the chemical property of gold element is stable and does not react with acid, its color remains unchanged. If it is not gold or impure gold, the path of gold disappears or changes.
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. When it really burns red, it is quenched into water and its color remains unchanged. It really doesn't change color when it meets fire, but it doesn't resist fire, and it becomes dark purple and not bright.