Gold is the quintessential symbol of status, power, immortality, and wealth, often restricted to royalty. The ancient Egyptians believed gold was the flesh of the sun god Ra. Gold is considered luxurious and precious because it is beautiful and easy to work. It does not tarnish, rust, or dissolve. Gold is hard to extract: Barely 50 grams come out of a ton of ore. It is also one of the best electrical conductors, which is why it is used so heavily inside computers and other technological equipment.
Below are some of the Gold tests that can be performed at
Checking Manufacturer Markings on Gold
The Stamp Test: Look for Hallmarks
A piece of gold jewelry is often engraved with a hallmark, which is a stamp that identifies its content and/or manufacturer. Hallmarks usually appear in an inconspicuous place like the inside of a ring. The standard purity scales are based on karats and millesimal fineness. The hallmark gold tests, also known as the magnifying glass test, is a good place to start when checking if your gold is real.
- Valid purity numbers under the Karat system (like 8k, 9k, 10k, 14k, 15k, 18k, 20k, 21k, 22k, 23k, and 24k)
- Valid purity numbers under the Millesimal Fineness system (333, 375, 417, 583 or 585, 625, 750, 833, 875, 916, 958, and 999)
- False purity numbers (anything other than the above)
- Manufacturer (like ESPO for Esposito, etc.)
Hallmarks show the gold’s level of purity and manufacturer to lend greater credibility to a piece’s authenticity and to make it easier to identify and verify. Since anybody can engrave any hallmark they choose, this level of the gold tests are not 100% foolproof.
If the numbers say anything other than the ones mentioned above, then you have fake gold. For example, 800, 925, and 950 do not refer to gold, but to silver. Why would they put 925 on gold? Because this often means the jewelry is gold-plated with a sterling silver base.
Any gold that is marked less than 10k (41.7% purity) is considered fake. Anyone familiar with the different levels of quality will quickly recognize the following markings:
GP, GF, GE, GEP, HGP, HEG
(Gold Plated, Gold Filled, Gold Electroplated, Gold Electro Plated, Heavy Gold Plated, Heavy Gold Electroplated)
These markings indicate that only a small percentage of gold was used to cover a piece that was made out of some other kind of metal to give it the appearance of gold.
To give you an idea of how the upper levels of purity stack up next to one another: 24k gold is 99.9% pure, while 18k gold is 75% pure. Absolutely 100% pure gold is unheard of, mainly because pure gold is very soft and wouldn’t make for a durable piece of jewelry.
Look for a Bluish or Greenish tint on your skin
Gold Tests are simple: It involves holding a piece of gold jewelry between your hands for a couple of minutes. The perspiration from your hands will either react with the metal and change the color of your skin or leave it unaffected. When real gold is in direct contact with your skin there is no discoloration. If the gold is fake it will cause your skin to turn black, blue, or green at the contact points.
One exception to this procedure occurs if you test gold on your skin while wearing a liquid foundation. When gold touches the makeup it will turn your skin black at the points of contact. Removing all makeup before the gold test makes this test more reliable.
Alternatively, makeup can also be used to test gold authenticity. Put on a liquid foundation and add powder over it. Once the makeup has dried, press the piece of jewelry against your skin and then run it lightly over the skin where you have the makeup. If the jewelry leaves a black track on the makeup, you probably have the real gold tests.
Gold is extremely nonreactive, so real gold jewelry will never discolor your skin. But using the gold makeup test is a unique way to also check if it’s real. If there are discolorations in gold jewelry it means you have an alloy where there are other metals mixed in.
Testing Gold with Household Items
Find any noticeable discolorations where the gold has worn away. Gold is pretty soft for metal, so plated gold often rubs away over time. The best places to check are around the edges of jewelry and coins. These spots often rub up against your skin and clothing throughout the day. If you see a different metal underneath the gold, you know your item is plated and not considered real gold.
For example, a silver coloring might indicate silver or titanium. A red coloring could mean copper or brass.
Note any discolorations on your skin from wearing or holding the gold. Pure gold doesn’t react with sweat or oil from your skin, so if you see black or green marks, they are from other metals. Silver leaves behind black marks and copper leaves behind green marks. If you see a lot of these marks on your skin, your gold may be less pure than you expect.
Keep in mind that most gold items are blends of gold and other metals. Even something like a 14K piece of jewelry, 58.3% gold, can leave these marks.
The Gold Size and Weight Test
- Compare a piece of gold you want to test with one that is already known to be real
- Use a set of calipers and a jeweler’s scale or use a Fisch Tester
- Gold is denser than most other metals. If you have a piece that looks too large for its weight or feels too light for its size, then you probably have fake gold.
Bullion coins are actual coins made from precious metals, including gold, silver, palladium, or platinum. They serve as collectibles, investments, or as a hedge against inflation.
Hold a strong magnet next to a piece of gold and watch for a reaction. Gold is not magnetic, so there should not be any attraction to magnets. If there is, you most likely don’t have real gold.
However, some of the base metals that can be mixed with gold are also non-magnetic so you can get a false read. The gold tests are not foolproof so it’s a good idea to do this in conjunction with another more accurate testing method.
Hold a strong magnet up to see if the gold sticks to it. For this test, you need a strong magnet capable of pulling even metal blends. Move the magnet over the gold and observe how it reacts. Gold isn’t magnetic, so don’t be fooled by anything that sticks. If the magnet pulls the gold toward it, your item is either impure or a fake.
Regular kitchen magnets might not be strong enough. For better accuracy, buy a powerful neodymium magnet from a home improvement store. The magnet test isn’t foolproof, since counterfeit gold can be made with non-magnetic metal like stainless steel. Also, some genuine gold items are made with magnetic metals such as iron.
Drop the gold into a jug of water to see if it sinks. Get a container big enough to hold both the water and the gold tests.
The water temperature you use doesn’t really matter, so lukewarm water is fine. Real gold is a dense metal, so it falls directly to the bottom of the jug. Imitation gold is much lighter and floats.
Real gold tests also don’t rust or tarnish when wet, so if you see discoloration, you probably have plated gold.
Rub the gold on unglazed ceramic to see if it leaves a streak. Make sure you’re using an unglazed piece of ceramic since anything with a glaze could affect the gold tests results. Drag your item across the plate until you see some fragments coming off the gold. If you see a black streak, that means your gold is not real. A gold streak usually indicates authentic gold.
Try getting an unglazed ceramic tile or a plate online or from your local home improvement store.
This gold test scratches the gold a little bit but doesn’t typically leave much noticeable damage. It is much safer than other tests involving scratches or acid.
Another way to do this is by spreading some cosmetic foundation on your skin and dragging the gold across it after it dries. Fake gold usually reacts with the foundation, leaving a green or black streak in it.
This is done by calculation. You need
- A scale (to weigh the jewelry)
- A container of water and
- A way to measure the level in millimeters (to measure the water levels before and after the jewelry goes into the water)
Now do the calculation: subtract the “before” measurement from the “after” measurement. Then divide the weight of the jewelry by the difference in the water levels. This gives you the density.
The standard density of real gold is 19.3 grams per milliliter (also written as 19.3g/mL). Not a lot of other metals come very close to it. If your calculation gives this figure or something very close to it, you probably have real gold.
Weigh your piece of gold on a scale. If you have a decent kitchen scale, place the gold on it. Otherwise, jewelers and appraisers often can do it for you for free. Call around to different jewelry or appraisal stores to see which ones offer this service. Make sure you get the weight in grams rather than ounces.
You need the weight in grams to use in a calculation later. If the weight is in ounces, you won’t get an accurate result.
- Fill a graduated cylinder halfway full with water. Choose a cylinder that is big enough to hold the gold. It needs to have measurement markings in milliliters (mL) or cubic centimeters (cc). If you don’t have a regular graduated cylinder, you could try using a kitchen measuring cup.
- Vials with frequent millimeter markings on the side are useful for getting a more accurate measurement during the test.
- The amount of water you use doesn’t matter that much as long as you leave plenty of space for the gold. If you fill the vial to the top, dropping the gold into it causes the water to spill.
- Read the starting water level in the cylinder. Look at the markings on the cylinder, then record the water level.
- This measurement is very important for the test, so write it down. Make sure you have the vial on a flat, level surface to get as accurate a reading as possible.
- Keep in mind that it doesn’t matter if your vial is marked in milliliters or cubic centimeters. They are the same measurement, so either unit can be used in the test.
Steps: Preparing and Weighing
- Drop the gold into the vial and record the new water level. Gently lower the gold into the cylinder to avoid losing any of the water.
- Let go of it right above the water to prevent splashing or getting your fingers wet. Then, read the markings again to get the second measurement.
- Write the second measurement down on a piece of paper. Note that this is the second measurement, not the initial one.
- Subtract the measurements to find the difference in the water level. To figure out how much water the gold displaced, subtract the initial measurement (the smaller number) from the final measurement.
- This gives you an answer in milliliters or cubic centimeters, depending on what measurement your vial lists.
For example, if you started with 17 mL (0.57 fl oz) of water that rose to 18 mL (0.61 fl oz), that leaves a 1 mL (0.034 fl oz) difference.
- Divide the gold’s weight by the difference in the water level. The density of the gold equals its mass divided by its volume.
- After calculating the density, compare the result to the standard density of gold, which is 19.3 g/mL. If your number is way off, chances are you have a fake.
Calculating the Results
- Keep in mind, though, that some combinations of metals in fake gold can have a density similar to real gold.
For instance, you have a gold item that weighs 38 g (1.3 oz) and displaces 2 mL (0.068 fl oz) of water. Divide 38 by 2 to get 19 g/mL, which is very close to the density of gold.
- The standard density differs a little depending on the type of gold you have. For 14k yellow gold, it’s about 12.9 to 13.6 g/mL. For 14K white gold, it’s around 14 g/mL.
- A piece of 18K yellow gold has an average density of 15.2 to 15.9 g/mL. A piece of 18K white gold has a density from 14.7 to 16.9 g/mL. Any 22K piece of gold has a density of around 17.7 to 17.8 g/mL.
For example, the purer the gold, the heavier it will be–and white gold is heavier than yellow. Therefore, the density of gold between 14k and 22k will be anywhere between around 12.9 and 17.7 for yellow gold and anywhere between around 14 and 17.8g/mL for white gold.
Gold testing is an essential part of any gold transaction. The gold acid test is a fast and accurate method to determine the purity of gold. This simple and reliable test will give you peace of mind that you are getting what you expect when investing in precious metals.
The process couldn’t be easier with a acid gold test kit, which includes all the tools necessary to get started. The kit contains acids, files, and color charts to help accurately identify your sample. All you need to do is scratch off a small sample of your piece and place it into the pre-measured solution contained in the bottle provided in your kit. After a few seconds, the acid will react with different types of metal creating distinctive colors on each type; this allows for precise identification of karats or fineness in gold samples.
Put a few drops of vinegar on the gold. Set your jewelry or gold piece onto a flat surface. Use an eyedropper to apply a bit of vinegar and let it sit for about 15 minutes. Real gold won’t change color, but fake gold will.
You can also submerge the gold in a glass container with vinegar for 15 minutes. This is a slightly riskier method because vinegar might damage semi-precious stones on gold jewelry.
The Nitric Acid Test
Gold is a noble metal which means it’s resistant to corrosion, oxidation, and acid. To perform this test, rub your gold on a black stone to leave a visible mark. Then apply nitric acid to the mark. The acid will dissolve any base metals that aren’t real gold.
If the mark remains, apply nitrohydrochloric acid, also called aqua regia (75% nitric acid and 25% hydrochloric acid) to the mark. This mixture dissolves gold so, if the mark disappears, the gold tests are real.
The Machine Tests to check the Gold
Electronic Tester (Sigma Metalytics Machine)
The Sigma Metalytics Precious Metal Verifier is calibrated for accuracy on a minute scale, enabling it to distinguish between metals in less than one second. While this equipment is good for measuring bullion and coins, Sigma Metalytics recommends the Kee Gold Tester for testing jewelry.
This machine sends electromagnetic waves into the item, passing through surface materials like wrapping or plating to read the resistance of the underlying metal. Its meter display is set to show a specific range of resistance that is or is not consistent with the resistance of each metal the machine has been calibrated to detect.
This machine works by sending X-rays through the gold and exciting its atoms into a higher energy state.
When the excited atoms return to normal they give off radiation. The machine monitors and analyzes this, using the radiation reading to identify the material. This method is fast and accurate. It is precise and far outperforms other methods while doing no damage to the items being tested.
In fact, none of these methods causes chemical or mechanical damage, so they will not jeopardize the value or integrity of your piece.
The Gold Fail-Safe Test
If you really want to know for sure how much gold is really in your gold, the most tried-and-true method of finding out is to take it to a reputable jeweler and have it tested there.
Jewelers have a wide array of methods available to the public for the authentication of gold tests content. Of course, nothing beats experience. But those who are trying to pass lesser metals off as real gold have become increasingly sophisticated in their “craft,” so even the jeweler will probably resort to machine verification to make sure.
Most home gold tests can give you an idea of whether or not your gold is real. While they are all good at showing probability, none are 100% conclusive.
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