We want to buy something that we not only like, but we also want to be honest. If we believe a fake thing, we will suffer monetary loss and destroy the trust between people, so we need to test the product we buy to identify its authenticity. The following are the methods we provide.
1、Weigh the weight of gold jewelry
Gold color and specific gravity relationship are tight. The higher the color is soft, the more inelastic, and the higher the pure gold, weighing in the hands, will slightly sink. The same volume of gold is far heavier than other metals and can also be directly considered to verify. But the shape is large and feels lighter with the hand. In that case, this gold jewelry will likely be adulterated, so you must be extra vigilant about the large and lightweight gold jewelry and carefully identify the authenticity.
2、Look at the color of the gold jewelry
We can distinguish pure gold, K gold, real gold, and fake gold according to the different luster and color of gold. The color of gold is greenish or white. It is not high purity. The color ruddy yellow purity is high purity.
3、Test the softness of gold jewelry
The higher the purity of gold jewelry, the softer and less flexible it will be. And after biting with teeth or scratching with a needle, it will leave traces. Pure gold is softer and generally not used to do inlaid jewelry, so where inlaid gold jewelry claims 24K, there must be a fraud.
4、See the gold jewelry mark
General regular channels of gold or gold jewelry are official signs, such as 24K gold marked “24K” or “AU 999”; 18K gold, marked “18K” or “AU750”, the color of gold jewelry is lower than l0K, according to the regulations can not play the K gold seal number. By checking the official mark, you can identify a part of the actual gold because regular merchants generally fear counterfeiting. At present, unscrupulous business people in society often create fake signs. Imitation stamps using diluted gold, sub-gold, and even brass as real gold, and thus identify gold jewelry to determine the authenticity and color level according to the sample for a comprehensive determination.
5、With gold jewelry scraping porcelain plate method
Find an unglazed porcelain plate. If you do not have one, take a random piece of porcelain from the home improvement store. Scrape the porcelain plate with gold. If there are black scratches on the porcelain plate, it is not real gold. If the scratches are gold color, it is absolute gold. This method will reveal fake gold but can also be misplaced if it is total gold.
6、Look at the hardness of gold jewelry
Gold of better color can leave traces after being scratched with sharp objects. After bending 2~3 times, 97% purity gold jewelry will show creases, usually called a fish scale pattern. On the other hand, gold jewelry of 95% purity will feel more challenging when bending. After bending, the fish scale pattern could be more precise. 90% purity gold jewelry will feel rigid when turning, and there is no fish scale pattern after bending. If there are more impurities in the gold, after bending many times, it may break, and the section will have apparent grit.
7、Listen to the sound of gold jewelry
If the purity of gold jewelry is 99% and above, throw it to the ground, it will make a dull sound and feel not much bounce. If it is fake gold jewelry, this sound is crisp, and there is no sluggish feeling. There will be an aftersound, and at the same time, after landing, there will be apparent ejection force.
8、Burning with the fire
Use fire to identify the gold jewelry to burn red (do not make jewelry melting deformation), after cooling to observe the color change, such as if the surface is still the original gold color is pure gold, such as color darkening or different degrees of black, is not pure gold. Generally, the lower the color, the more intense color, all black, that is fake gold jewelry. It burns red quenched into the water, and the color remains unchanged. The actual fire does not change color. The fake is not fire-resistant and becomes black, purple, and not bright.
9、Test the color with a touchstone
People often use touchstone to determine the general content of gold; touchstone is a kind of carbonaceous quartz and opal and other mixed black minerals, the gold in the touchstone above a streak, you can see the general color of gold.
Pure gold: shiny dark yellow, rich yellow;
Containing silver gold: light color change slightly with inflammation green;
Containing silver more than 25% of gold: earth white;
Containing copper gold: color deepening, red hue;
Contains silver, copper, gold: yellow;
Containing zinc, with nickel gold: white gold.
This method should be carried out under natural light and fluorescent lamps, not direct sunlight and incandescent lamps.
10、Nitric acid test method
Test gold jewelry with Nitric acid because the chemical stability of gold elements does not react with acid, so the color remains unchanged. The gold is gone or changed if the non-gold or non-pure gold is. The law of change is “three fast, three slow”; that is, the low color disappears fast, the high color fades slowly; mixed gold disappears fast, pure gold disappears slowly; big mixed gold disappears quickly, and tiny mixed gold disappears slowly.
A drop of nitric acid on the gold; observe the reaction.
If the acid drop appears green, the gold is either made of ordinary metal or gold-plated.
If it appears golden, then it is gold-plated copper.
If it appears milk-colored, it is gold-plated silver.
If there is no reaction, then the gold is real.
11、Test gold with a magnet
Use a magnet to suck gold jewelry. Gold is not a magnetic metal, so it is fake if the appeal can attract the jewelry. However, the fact that it cannot be drawn by a magnet alone does not prove that this gold jewelry is authentic because it may also be made of other non-magnetic metals.
12、Density test method
We can operation of the following four steps.
(1) Weighing. If you do not have your balance, you can ask the jeweler to help you weigh it, usually free of charge. The weight should be accurate in grams.
(2) In a small bottle filled with water. If there is a millimeter scale on the wall of the beaker, it is best; it will help you to complete the test more efficiently. The amount of water does not matter as long as the water does not overflow after the gold jewelry is put in, so do not fill the water. Before and after putting in the gold jewelry, you should carefully note down the height of the water level.
(3) Put the gold jewelry into the measuring bottle. Record the change in water level before and after, then calculate the increase in water volume accurately to milliliters.
(4) Calculate the density with the following formula. Gold jewelry density = total weight of gold jewelry/volume of water increase. If the thickness is close to 19.32 g/ml, it is real gold or metal with a density comparable to gold. The following is an example of how to calculate density.
The gold piece weighs 38 grams, and the volume added by water is 2 ml. The density obtained according to the formula is 19 g/ml, which is very close to the thickness of natural gold.
Note: The density of gold varies with different purity
14K gold density is equivalent to 12.9-14.6g/ml
Yellow 18K gold density is equivalent to 15.2-15.9 g/mL
White 18K gold density is equivalent to 14.7-16.9g/mL
22K gold density is equivalent to 17.7-17.8g/ml
13、Bromine reagent to judge
First, we put the gold product into the alcohol solution, shake it for a while, then dip a piece of filter paper into the alcohol solution, the filter paper will turn grayish purple at this time, then drop a few drops of bromine onto the filter paper, if the color turns white, then the product is real gold, and vice versa is fake gold.
14、Use liquid foundation
Apply a thin layer of foundation on your hands, and after the foundation dries, rub the gold jewelry back and forth on your hands. Pure gold jewelry will leave a line on the skin where the foundation has been applied; if not, the jewelry may be gold-plated or made of other metals, not pure gold.
15、XRF precious metal analyzer
Many jewelers like to use this instrument to quickly test the color of metal jewelry. However, precious metal analyzers are generally very expensive. Use the jewelry on the instrument’s scanning board, turn on the switch, and wait for the machine to display the readings. All indicators can visualize at a glance. In addition, the handheld electronic gold detector is also a relatively straightforward instrument to test gold and relatively cost-effective; its small size, one end with a probe, testing, first a gel with conductivity coated in jewelry, and then the investigation against the jewelry to move back and forth, the response of the metal to the current can indicate whether it is pure gold. Gold has good electrical conductivity, so in the detector, pure gold jewelry than gold-plated jewelry shows higher readings. However, when using the sensor, you should strictly follow the instructions.
The spectrometer is a precious metal inspection analyzer that can accurately detect gold products’ metal content with detailed data. The comparison of various reference indicators will determine the authenticity of gold products.