Methods 1: Use household articles to check gold.
1, put the gold in the water to see if it will sink. Find a container that can hold enough water and the gold products you want to test. The water temperature will not affect the test results, just warm water. Real gold has a high density and will sink directly to the bottom. Imitation gold products tend to be lighter, so they may float. Real gold will not rust or lose its luster even if it is wet. So if you find discoloration, it's probably just gold plating.
Drop a few drops of vinegar on the gold. Put jewelry or gold on a flat surface. Drop a little vinegar with a dropper, and then let it stand for about 15 minutes. Real gold does not change color, while fake gold generally changes color. You can also soak gold in a glass container filled with vinegar 15 minutes. This method is slightly risky, because vinegar may damage the semi-precious stones on gold jewelry.
3. Is there any obvious color difference where you see through it? Gold is a very soft metal, and the gold-plated layer often wears away for a long time, while the edges of jewelry and coins often rub against skin and clothes, so they are the best places to test authenticity. If you find other metals under the coating, then this thing is only gold plated, not real gold. For example, silver can be silver or titanium. Red may be copper or brass.
Expert tips
Jerry ehrenwald
Jerry Ehrenwald, president and gemologist of the International Jewelry Association, is a gemologist in new york, USA, and a senior jeweler certified by the American Association of Appraisers. He is the former president of the International Jewelry Institute, and the American patent technology Laserscribe? The inventor of this technology used laser to carve unique marks on diamonds, such as DIN diamond identification code. He is a senior member of American Appraisers Association (ASA) and a member of new york 24k Jewelry Club, a social club limited to 200 top achievers in the jewelry industry.
Jerry ehrenwald
President and gemologist of the International Jewellery Association.
Our experts believe that discoloration or suspicious spots on the edge of an item usually indicate that it is not gold. However, some gold less than 24K may lose its luster after a long time, because the cheap metals contained in it are oxidized by air.
4. Observe whether there are traces caused by wearing or touching gold on the skin. Pure gold will not react with sweat or grease on the skin, so if you see black or green marks on the skin, it is from other metals. Silver will leave a black mark, and copper will leave a green mark. If obvious traces are found on the skin, it means that gold may not be as pure as you think. Remember, most gold products are alloys of gold and other metals. Even 14K jewelry with a gold content of 58.3% will leave such a mark. Other tests can also be used to verify the authenticity of gold.
5. Absorb gold with a strong magnet. This detection method requires that the magnet has strong magnetism, and it must be ensured that it can also adsorb magnetic metals when mixed with various metals. Shake the magnet above the gold product and observe its reaction. Gold has no magnetism, so it will not be attracted by magnets. If a magnet is attractive to it, it is either impure or fake. Ordinary magnetic kitchen utensils are not suitable. You may have to buy a strong neodymium magnet in a household goods store.
Magnetic detection is not a foolproof detection method. Some imitation gold products may be made of nonmagnetic metals such as stainless steel, and some real gold products may also contain magnetic metals such as iron.
6. Rub unglazed porcelain with gold to see if it will leave traces. Be sure to use unglazed porcelain. Glazed porcelain will affect the test results. Drag the gold you want to test on the porcelain plate until you see something scraping it off. If you see black lines, then this thing should not be real. If it is gold, it should be real gold. Try to find an unglazed tile or plate online or in a local household goods store.
This test method will scrape off a little gold, but usually it will not cause obvious wear and tear to this item. This method is much safer than other tests that require friction or acid.
Another way is to apply a little foundation to your skin, and when it is dry, drag your gold ornaments on this foundation. Imitation gold products often react with foundation, thus forming green or black marks.
Method 2: Check the manufacturer's mark.
1, looking for official figures engraved on gold. The mark or purity mark on gold will tell you how much gold this item contains. Purity marks are generally engraved on the buckles of jewelry, the inside of rings, and the surfaces of coins and gold bars. Different evaluation systems have different marks, such as writing the number 1 to 999, or engraving the mark from 0K to 24K. Read the purity mark with a magnifying glass. Purity marks are generally small, and the marks on small objects such as rings are even more difficult to see with the naked eye.
Jewelry of a certain age may not see the purity mark clearly. Some have been worn for a long time, and some may not be marked at all. Purity labels became popular in some places after 1950s. In India and other regions, the use of purity marks was not compulsory until 2000.
2. Use the marked numbers to judge the purity of gold. Most coins and jewels are not pure gold, but are generally mixed with other metals. There are two ways to record purity marks. In Europe, the number 1 to 999 is used to mark the purity, and 999 means pure gold. In the United States, the scale is 0 to 24K, and 24K refers to pure gold. Digital marks are easier to identify than carats. For example, 375 means that this thing contains 37.5% gold.
Different countries have different criteria for judging gold. For example, in the United States, nothing below 9K can be counted as gold. But in fact, 9K bracelet contains 37.5% gold.
Counterfeits will also mark themselves with purity marks for simulation. Unless you are sure that you have gold, don't take the purity mark as your only judgment basis.
3. Look for letters indicating that gold is impure. Letters commonly used to represent impurities are GP, GF and GEP. This letter means that your things are gold-plated, which means that the manufacturer has plated a thin layer of gold on metals such as copper or silver. Although this thing contains gold, it is still not real gold. GP stands for gold plating, GF stands for gold plating and GEP stands for electroplating gold.
The origin of gold may also affect the above mark. For example, Indian gold will be engraved with a small triangle mark, indicating that the item is rated by the government Committee. Jewelry and other items will also be marked with grade numbers and letters, such as K.
Method 3: Test density
1. weigh your gold. If you have a decent kitchen scale, weigh the gold on it. If not, you can also ask the jeweler or jeweler to weigh you for free. Call different jewelry stores or treasure stores to see which one can provide this service. The measurement should be in grams, not ounces. Record the weight in grams so that you can calculate the density later. If the unit is ounces, you can't get accurate results in the end.
2. Fill the measuring cylinder with half a cylinder of water. Choose a cylinder big enough to hold your gold products. The cylinder should be marked with milliliter (mL) or cubic centimeter (cc). If there is no conventional measuring cylinder, you can also use a kitchen cup instead. Using a small number of bottles marked with dense millimeter scales next to them can make the measurement results more accurate.
As long as there is enough space to accommodate gold products, it is not very important to measure water consumption. There should not be too much water in the measuring bottle, or the gold products put in will overflow the water in the bottle.
3. Record the initial water level line in the measuring cylinder. Record the amount of water in the measuring cylinder according to the scale line on the measuring cylinder. This initial water level is very important, so write it down. In order to obtain as accurate a value as possible, the measuring container should be placed on a plane without inclination. It doesn't matter whether the scale of the measuring bottle is millimeter or cubic centimeter. They are the same unit of measurement and can be used to calculate density.
4. Put the gold into the measuring container and record the new water level. Gently put the gold into the measuring cylinder, and be careful not to overflow the water in the cylinder. Put the gold near the water surface to avoid splashing water or wetting your fingers. Then read the new water level line according to the scale. Write the second measurement result on paper, and pay attention to distinguish it from the first measurement result.
5. Subtract the two measurement results to get the water level difference. Subtract the first measurement result from the second measurement result, that is, the smaller value, so that the gold equivalent of water can be obtained through simple calculation. Because different measuring containers have different units, the final result may be millimeters or cubic centimeters. For example, if the initial water level rises from 17mL to 18mL, the water level difference is 1mL.
6. Use the weight of gold to impose water level difference. The density of gold can be obtained by dividing its mass by its volume. After obtaining the density, compare it with the standard density of gold 19.3 g/mL. If the values are far apart, then this thing is probably fake. But a similar density is not necessarily real gold, because some metal mixtures can reach a density similar to that of gold. If you have a piece of 38 grams of gold, and the same volume of water is 2mL, then 38 divided by 2 equals 19 g/mL, which is very close to the density of gold.
Different kinds of gold have slightly different densities. For example, the density of 14K gold is between 12.9 and 13.6 g/mL, while the density of 14K platinum is about 14 g/mL.
The average density of 18K gold is between 15.2 ~ 15.9g/mL, while the density of 18K platinum is between 14.7 ~ 16.9g/mL.
The gold density of 22K is between 17.7 ~ 17.8g/mL.
Method 4: Test with nitric acid
1. Buy a set of tools for testing gold to get the acid you need. The test kit contains various nitric acids and can be used for different gold. Some suits even have a flat stone called touchstone, with which you can scrape a small amount of gold from your gold products. Some suits may have gold or platinum sample needles. You can compare them with yours. You can buy such a test suite online. You can also visit the local jewelry store. Most jewelers will use this method to identify the authenticity.
Make a small scratch on the gold with a sharper tool. Find an inconspicuous place to cut your jewelry, such as under a belt buckle or inside a ring or bracelet. Then scrape the gold with sharp tools such as jewelry carving machine until the surface of the gold is cut, revealing a brand-new layer of gold or other metal layers hidden below. Nitric acid test needs to cut your gold. If this item has special meaning to you, or you plan to collect it, you'd better give it to a professional jeweler instead of doing the experiment yourself.
3. Drop a drop of nitric acid on the scratch. Using nitric acid is risky, so wear latex gloves and choose a well-ventilated room. When I was ready, I found the bottle of nitric acid marked 18K Kg gold. Put the gold in a stainless steel container, drop a drop of nitric acid on the scratch just made, and then see if it will turn green. If it turns green, it means it is fake gold. Ordinary gold will not react with this acid. The reaction is either gold plating or low purity metal mixture.
If nitric acid turns into the color of milk, it means it is a gold-plated silver product. If nitric acid turns golden, it means gold-plated brass.
4. Use touchstone to test the purity of gold. If you think the gold in your hand is real, rub it against the touchstone and let it leave a golden scratch on it. Then drop 12K, 14K, 18K, 22K nitric acid in different parts with scratches for gold exchange. After 20 to 40 seconds, you can judge the purity of gold by looking at the place where the scratch has not dissolved. The concentration of nitric acid for detection increases in turn, so the concentration of nitric acid for 22K is stronger than that for12K.. If 18K nitric acid dissolves gold and 14K nitric acid does not, then your gold purity is about 14K.
Expert tips
Jerry ehrenwald
Jerry Ehrenwald, president and gemologist of the International Jewelry Association, is a gemologist in new york, USA, and a senior jeweler certified by the American Association of Appraisers. He is the former president of the International Jewelry Institute, and the American patent technology Laserscribe? The inventor of this technology used laser to carve unique marks on diamonds, such as DIN diamond identification code. He is a senior member of American Appraisers Association (ASA) and a member of new york 24k Jewelry Club, a social club limited to 200 top achievers in the jewelry industry.
Jerry ehrenwald
President and gemologist of the International Jewellery Association.
For complete peace of mind, it's best to let people in the industry help you identify the authenticity.
Tip: Most methods of testing gold have certain limitations, so in order to make sure your gold is real, do more experiments.
You should have heard the test of biting gold with your teeth. It is said that this can leave teeth marks on real gold. But most gold is mixed with other hard metals, so don't try it to protect your teeth.
24K gold ornaments mean that the purity of gold is 99.9%, which contains trace amounts of other metals. And 22K gold means that the ratio of gold to other metals is 22 to 2.
Items with a purity of less than 24K will change their hardness and color because of mixing with other metals. Gold itself is a very soft metal, so in order to make it more durable, people will add metals such as silver and copper to it.
Jewelry made of platinum, gold, red gold and rose gold is actually a mixture of gold and other metals.
If you need to determine the authenticity of gold, you'd better ask a professional jeweler or appraiser to identify it for you.
Warning nitric acid is a strong acid, which will burn the skin and damage precious gold. If you have concerns, try to detect gold in household vinegar. Acetic acid is milder than nitric acid You can also ask a professional jeweler or appraiser to do a nitric acid test for you.
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