Since ancient times, the Chinese have had a “gold fixation”, buying up about 40% of the world’s gold production every year.
So how do we determine whether the gold we are paying a lot of money for is real or fake, pure or mixed?
How can gold be purified?
Now let’s talk about the method of gold purity identification.
The higher the purity of gold after smelting, the brighter and darker the color will be.
Generally in the gold content is higher than 95%, can reflect the wealth of gold gold, rich and brilliant eyes;
If the gold is 90 to 95 percent pure, it will be a little reddish yellow in color and less bright.
80-85% pure gold, light yellow will take the feeling of green yellow;
65%-70% pure gold, green yellow will also have a clear white light;
50% to 60% pure gold, only a faint yellow;
If there is no 50% purity, the whole hair is white and white.
Teeth biting gold is actually a test of the hardness of gold.
This method can filter out some of the less pure gold.
Pure gold has a low hardness and can leave teeth marks if you bite into it.
Therefore, when identifying pure gold, you can try its hardness, if the hardness is too high, it can not be pure gold.
(With the exception of 3D hard gold) this simple and effective method is generally not recommended because of the possible damage to teeth.
In addition, because lead is softer than gold, gold-plated lead can also leave bite marks, causing identification errors.
1, first of all, to bite the gold properly.
2. See if there are bite marks on the gold.
In theory, real gold leaves bite marks when bitten, and the deeper the bite, the higher the purity of the gold.
Method 3: The purity of pure gold and pure gold jewelry is very high, and it is really calm. The sound of the jewelry falling or colliding with each other will be low, dull and steady, which is the sound of “smacking”, and it will not move immediately after falling.
The color is poor, the purity is low, and even when the fake gold lands or bumps against each other, it will make a metal sound of “dang-dang-dang-bang”, and sometimes it will beat, and it will beat after landing.
But don’t knock it too hard. Be careful.
Method 4: Fire method of pure gold is extremely high temperature refined out of cooling formed, gold will not change color in case of fire, but generally iron ore will turn black in case of fire.
If the fire burns, the gold mixed with more impurities will burn black, while the pure gold will not change color and remain golden.
But don’t burn it for too long or it won’t deform.
Method 5: density test method 1, weighing.
If you do not have your own scale, you can ask the jewelry to help you weigh, generally free.
The weight should be accurate to grams.
2. Fill a small bottle with water.
It is best to have a millimeter scale on the side of the vial, which will make it easier for you to complete the test.
It doesn’t matter how much water you have, as long as the water doesn’t overflow after the gold is put in, so don’t fill it up.
Make careful note of the water level before and after placing the gold.
3. Put the gold into the measuring bottle.
The change in water level before and after was recorded, and then the increase in volume of effluent was calculated, accurate to milliliters.
4. Calculate the density using the following formula.
Gold density = Total weight of gold/volume added by water.
If the density is close to 19 grams per milliliter, it is real gold, or a metal with a density close to gold.
According to the formula to calculate the density, this result is close to the density of real gold can be confirmed.
Note that the density of gold varies according to its purity: 14K gold corresponds to 12.9 to 14.6 g/ml yellow 18K gold corresponds to 15.2 to 15.9 g/ml white 18K gold corresponds to 14.7 to 16.9 g/mL 22K gold corresponds to 17.7-17 to 8 g/ml Method 6:
Spectral analysis in order to strictly detect the purity of gold jewelry also have to find professional institutions through X-ray spectrum analyzer to test the sample, can be nondestructive analysis of gold and other impurities in the sample content, the general accuracy can reach 99.9%.
The above is a small series to introduce you to the problem of how to identify the purity of gold. Please pay attention to more knowledge.
