Lao Fengxiang (joined the stock selection, participated in the simulation of stocks) There are many methods for the identification of gold jewellery. The Chinese folks have summed up a set of simple methods. The slogan is: look at color, weight, sound, hardness, stone grinding, acid point, Color. The first four sentences rely on eyesight and the feelings; the last three sentences require tools and reagents. Lao Fengxiang (join the stock selection, participate in the simulation of stocks) how to identify gold jewelry? There are many methods for identifying old Fengxiang gold jewellery. The Chinese folks have summed up a set of simple methods. The slogan is: look at color, 掂 weight, listening to rhyme, folding hardness, stone grinding, acid point, and color. The first four sentences rely on eyesight and the feelings; the last three sentences require tools and reagents.
First, look at the color
According to the different luster and color of gold, it can be roughly distinguished from pure gold, K gold, real gold, and fake gold. That is, gold is preferably reddish yellow, the color is above 95%; the positive yellow color is about 80%; the blueish yellow color is about 70%; the yellowish slightly grayish color is about 50%. Therefore, there are mouths for "seven green, eight yellow, nine five red, yellow and white with gray to half gold." For the jewelry that has been in the first time, there is a saying that "the copper turns green, the silver turns black, and the gold never changes color."
Second, the hardness
Gold is characterized by ductility and low hardness and can be pressed into sheets having a thickness of 12.7 microns. When the color is high, scratching with a pin or nail can leave marks. More than 97% of the gold jewellery, after bending two or three times, wrinkles appear at the bend, also known as fish scales; 95% of the color of the gold jewelry, feels hard when bent, fish scales are not obvious; 90% of the color of gold Jewelry, hard when bent, no fish scales; gold jewelry with more impurities, bent two or three times to break; if it is made of raw gold, the bend is broken, the section has obvious sand-like shape. When using this method, the width and thickness of the jewellery should be considered. The thickness and width are harder, and the thinner and narrower are softer.
Third, listen to the rhyme, see the elasticity
When the high-quality gold jewellery is hit or hit hard, it gives a dull, low-pitched sound, and has no phonology and no elasticity. K gold has phonology, sound, elasticity, and elasticity. The sharper the longer, the worse the color.
Fourth, see the density
The density of gold is 19.32 g / cm 3 , which is about twice as much as the same volume of silver, lead and tin. Available formula: the quality of a certain gold jewelry (gram) is equal to the density of a certain gold jewelry (cubic centimeters). Find the density of the gold jewelry to be measured. The density is 19.32 g/cm3, which is pure gold or pure gold. Otherwise, it is non-pure gold or color difference gold (this method has no destructive effect on jewelry).
5. Identify the color with touchstone
Use the gold pair card (the gold medal that has been determined to be the color) and the jewelry to be honed on the touchstone to determine the color of the gold jewelry by comparing the colors. This method should be carried out under natural light and fluorescent light, and not under direct sunlight and incandescent light.
Sixth, use acid point
On the touchstone, the jewels of the identified jewellery and the counter are separately ground, and the glass nitrate is used to test the nitric acid on the ruthenium. Because the gold element is chemically stable and does not react with the acid, the color does not change. If it is not gold or non-pure gold, the Golden Road will disappear or change. The law of change is "three fast, three slow", that is, the low color disappears quickly, the high color disappears slowly; the mixed gold disappears quickly, the clear gold disappears slowly; the large mixed gold disappears quickly, and the small mixed gold disappears slowly. Depending on the disappearance of the Golden Road, the comparison of the cards will determine the quality of the gold jewelry.
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