How to identify the authenticity of gold jewelry?

Gold jewelry refers to jewelry made of gold as the main raw material. The chemical symbol of gold is AU, with a gravity of 17.4 and Mo's hardness is 2.5. Gold jewelry can be divided into two categories: pure gold and K gold in terms of gold content. The gold content of pure gold jewelry is more than 99%, and it can reach up to 99.99%. K gold jewelry is a jewelry made of other metals (such as silver, copper metal) to its golden materials, also known as "opening gold" and "color gold". Due to the number of other metals, different K numbers of K gold jewelry are formed. The size and gold content of the K number are as follows:

24K, 99%or more; 22K, 91.7%; 21K, 87.5%; 18K, 75%; 14K, 58.5%; 12K, 50%; 10K, 41.66 %; 9K, 37.5% 8K, 33.34% 6K, 25%

In gold jewelry, pure gold jewelry texture is soft, teeth are bite, and they are easy to bend. I feel heavy and feel heavy. K -gold's head jewelry texture is slightly harder, the teeth bite the use of mintes, the color is yellow in yellow, and the number of K is reduced, the white increases, and the yellow is shallow. The feel of K gold jewelry is not as heavy as pure gold jewelry. In addition, both pure gold and K gold jewelry have a printing sign. Printing on gold jewelry is used "gold" and "KG" English letters represent the texture. When indicating the gold content, the word "99" or "24K" indicates that it is pure gold jewelry. The K gold jewelry is marked with the corresponding K number, such as the K gold jewelry marked "18K". %. In addition, the jewelry also marks the printing of the origin of different manufacturers. Really gold jewelry, printing standards, completeness, and clear, is an important identification of judgment.

The types of jewelry that is easily confused with gold jewelry, some are gold -plated jewelry, some are gold jewelry, some are copper jewelry, and some are copper alloy jewelry. Let's explain all the brief explanations:

The gold -plated jewelry is plated on the surface of other metal jewelry on the surface of the electroplating method. Essence However, the gold -plated jewelry feels lightly, the texture is hard, the teeth are bitter, and it is easy to fade with a long time. Some gold -plated gold -plated jewelry, the color is either red or white, or flowers.

This gold jewelry refers to 24K or 22K gold foil on other metal surfaces, such as the KD number of K is too low, and its softness is poor. The appearance of the golden jewelry is similar to the real gold jewelry. The golden light is sparkling and it is not easy to fade, making it difficult to argue. However, if you carefully observe the depression, angle, back, etc. of the jewelry, you can find that the gold foil is uneven and there is a phenomenon of tilting edges. If there are broken joints on the jewelry, the cross section of the metal material can be seen from the outside. In addition, the feel of the gold jewelry is also lighter, the texture is harder than the pure gold jewelry, the teeth are bitter, and it is not easy to bend.

The copper jewelry color is yellow with red, fake, darker luster, soft texture, and light weight. Copper alloy jewelry (copper tin alloy), white color, hard and light quality, long -term coloring, will make the skin darker.

The gold -plated jewelry, gold jewelry, or copper jewelry, and Asian gold jewelry, generally do not have a gold jewelry -like printing. Or it is different from gold jewelry. If some jewelry is engraved with the English letters "GK", it means "gold plating". Or the signature traces are blurred and crooked. Consumers should identify whether there are printing, printing whether the printing is in compliance with the above provisions, and whether the printing is clear, etc. to determine the authenticity of gold jewelry. rnrn　　黄金首饰的鉴定方法很多，中国民间总结了一套简便方法，其口诀是：看色泽、掂重量、听音韵、折硬度、石上磨、对比牌、用酸点、 Fixed into color. The first four sentences depends on the eyes and the feeling; the latter four sentences need to be used by tools and reagents.

. Look at the color
The different luster and color of gold can be generally distinguished from pure gold, K gold, real gold, fake gold. That is, gold is better with red yellow, and the color is more than 95 %; the positive yellow color is about 80 %; the blue and yellow color is about 70 %; the yellow color is slightly gray and the color is about 50 %. Therefore, there is a formula for "seven greens, eight yellow, nine five red, and yellow leucorrhea ash. For jewelry from Jiu Tibet, there will be a saying that "copper turns green, silver turns black, and gold will never change color".

. Look at density
The density of gold is 19.32 grams / cubic centimeter, which is about double the same volume of silver, lead, and tin. Available formula: The mass (gram) of a certain gold jewelry (gram) is equal to density than the volume (cubic centimeter) of a certain gold jewelry (cubic centimeter). Seeking the density of the gold jewelry measured, the density is about 19.32 grams / cubic centimeter, it is pure gold or relatively pure gold, otherwise it is a non -pure gold or color difference gold (this method has no destructiveness to the jewelry).

. Folding hardness
Gold has the characteristics of ductility and small hardness, which can be compressed into a thin piece of 12.7 microns. When the color is high, marks can be left with large head needles or nails. More than 97 % of gold jewelry, after twisting two or three times, wrinkles appear at the bend, also called fish scales; about 95 % gold jewelry, feel hard when bending, the fish scales are not obvious; The jewelry is very hard when the bending is bent, without fish scales; gold jewelry containing more impurities, bend twice or three times to break; if it is made for raw gold, the bend is broken. When using this method, the width and thickness of the jewelry should be considered. The thick and width should be hardened, and the thin and narrow ones are softer.

. Listening to the rhyme, watching elasticity
When the high -quality gold jewelry is knocked out or threw it hard, it emits a dull sound of "daedy, dwelling", and no sound rhyme, no elasticity, K gold rhyme, sound sound, sound sound, sound, sound, sound, sound, sound, sound, sound, sound, sound, sound, sound, sound There are elasticity, the greater the elasticity, the more the rhyme, the more older, the worse the color.

. Use the test gold stone to identify the color
Plip the gold -pairing card (the gold medal that has been determined) and the test jewelery on the test gold stone, through the contrast color, determine the color of the gold jewelry. This method should be carried out under natural light and sunlight, and cannot be carried out under the direct sunlight and incandescent lamps.

. Use the acid point
The golden roads that have been identified and the cards are grinded on the test stone. Trying nitric acid on the golden road with a glass stick. Because the chemical properties of the golden element are stable and do not react with the acid, the color remains unchanged. If it is not gold or non -pure gold, the Golden Road disappears or changes. The law of changes is "three fast, three slows", that is, the low color disappears quickly, and the high color disappears slowly; Depending on the disappearance of its golden road, compare cards can determine the color of gold jewelry.

Putting gold in dilute sulfuric acid is fake

The easiest way is to bite with your teeth