Magnetism is a force in physics that affects almost every element on earth; it can either attract (pull closer) or repel (push away). The forces of magnetics don’t affect every material. They can only attract or repel objects which contain a magnetic element, such as iron. Many base metals, including nickel, zinc, and cobalt, are all attracted to a magnetic field. Noble metals, on the other hand, are known to be impervious to magnets. This applies to silver, platinum, and yes; gold.
As a noble metal, real gold cannot be magnetic. Fine .999 pure gold of good quality will neither attract nor repel when faced with a magnetic field. However, checking if your gold is magnetic is one of the primary ways to see if gold is real. If you want to be sure a piece of gold you have is genuine, you can test it using magnetism. There’s a lot to learn about this fascinating subject, so in this article, we’ll dive a little deeper into the different magnetic properties of precious metals.
We’re going to discuss the different ways, including using magnetic fields, that you can test if gold is fake. We will also explore the possibilities of magnetizing gold and other precious metals, and how these properties can be useful. The chemical element of gold has many physical and chemical characteristics which make it unique, and this is also one of the reasons why gold is so valuable. Read on to find out everything you need to know about magnetism, and how to use this force of science to check if you own real gold.
What makes a Metal Magnetic?
Magnetism is created by an uneven distribution of electrons in the atoms of certain metals. This causes an irregular rotation and movement of the electrons within the atom, leading them to shift backward and forwards to create magnetic dipoles. The dipoles then align, creating a magnetic domain, and a north and south pole. Every magnet has a north and south pole; opposite poles attract each other, while identical poles repel from each other.
In a non-magnetized material, the magnetic domains are not aligned, so the poles face in opposite directions. This cancels out the magnetic force, and the material will not attract or repel anything.
Even a magnetic material, such as iron, can be non-magnetized and will not attract other metals. In the same way, a material which was previously not magnetic can have its domains aligned, creating a magnetic field.
Different Types of Magnets
There are several different categories in which we can sort magnets, as not all magnetic materials have the same properties. These different types of magnets can serve different purposes and functions and are useful in all sorts of industries.
- Permanent magnets: Also known as hard magnets, permanent magnets produce a constant magnetic field. This is the strongest form of magnetism, caused by ferromagnetism. This type of magnet is the most common to people, you’ll probably find one on your fridge.
- Temporary magnets: A temporary, or soft magnet is only magnetic when in the presence of a magnetic field. Once the field is removed, the material loses its magnetism. One example is paperclips; when placed near a hard magnet, many paperclips will attach together from the forces of magnetism. Each paperclip becomes a temporary magnet, but it cannot retain these properties once the magnet is removed.
- Electromagnets: Electromagnets are made from a coil of wire, which needs an electric current to pass through in order to produce an electromagnetic field. Electromagnets are incredibly useful pieces of technology, used in everyday objects like your computer or doorbell.
What Materials Are Magnetic?
Most elements in the universe can be classed as one of three categories, according to their magnetic properties. Many materials will react very differently to one and other in the presence of a magnetic field, depending on their atomic and molecular structure. To understand the magnetic properties of gold and other precious metals, you need to understand how and why different elements fit into these categories.
The first classification is Diamagnetic materials, which have a weak, negative susceptibility to magnetic fields. Diamagnetic elements are slightly repelled by magnetic fields, but this property disappears when the external magnetic field is removed. That means that diamagnetic materials are temporary magnets. In these elements, all electrons are paired, so there is no irregular movement to create magnetic dipoles. Most periodic elements fall into the diamagnetic category, including copper and silver.
Where diamagnetic materials have the tiniest negative susceptibility to magnets, paramagnetic materials are the opposite. They have a very slight positive susceptibility to magnetic fields and are also temporary magnets. Paramagnetic elements have unpaired electrons that can be realigned when exposed to an external magnet and cause a slight attraction between the two materials. Some examples of paramagnetic materials include lithium, magnesium, and aluminum.
The final category of magnetic elements is ferromagnetic materials, which as we mentioned earlier is the strongest form of magnetism. These elements show a large, positive susceptibility to external magnetic fields, and can retain their magnetism after the external force is removed. Ferromagnetic materials also have unpaired electrons and strong magnetic domains. Ferromagnetic materials can still be non-magnetized when their atoms are in a disorganized state. However, after a magnetic force has been applied, the domains align and the material can produce a strong magnetic field. Iron, nickel, and cobalt are all strongly ferromagnetic elements.
Is Gold Magnetic?
Scientists have spent years debating the subject of whether gold is magnetic, as this fascinating element exhibits magnetic properties in a very unique way. Gold is technically classified as a diamagnetic material. This means it cannot form a permanent magnet or be attracted to a magnetic field, but it is possible for it to repel slightly. However, if we look at gold on an atomic scale, we can see that it has an odd number of atoms.
We already learned that unpaired electrons create either paramagnetic or ferromagnetic materials, while paired electrons from diamagnetic material. How, then, can gold be diamagnetic? The answer lies in the sheer density of solid gold. Gold is one of the densest elements on earth, which is one of the things humans so desire about it, at 19.32 grams per cubic centimeter. This property of gold means when in solid form, the metal’s electrons are packed very closely together. Rather than aligning, the electrons bond with each other and form complete pairs, making the material diamagnetic.
If we take things down to the nano-scale, it’s a completely different story. Gold has an uneven number of electrons as a single atom, meaning gold nanoparticles are paramagnetic. They still cannot create a strong magnetic field but can exhibit magnetic properties. The more particles of gold that cluster together, the more pairs of electrons form. That means as a piece of gold gets larger, it’s magnetic properties become weaker.
Pure gold is not magnetic, and cannot form a magnetic field on its own. If you apply a magnetic field to solid gold, it can become slightly magnetized and very weakly repel the magnet. Gold bullion, including coins and bars, is generally more than 99% pure gold, and the alloyed materials are commonly other non-magnetic metals such as silver. It is possible that a gold alloy with at least 20% of its atoms made of a magnetic material, such as iron, could magnetize on its own.
Is Gold Jewelry Magnetic?
Because gold jewelry is not necessarily made up of 100% gold, it is possible that some parts of gold jewelry can become magnetized. Jewelry made from gold is almost always alloyed with a harder material to make it more durable, but these metals are also generally non-magnetic. The only case where real gold jewelry might attract a magnet is if the clasp, fastener, or other external element is made from a ferromagnetic material. Sometimes harder-wearing metals are used at these weak points to ensure no precious jewelry is lost.
How to Test if Gold is Real
Nowadays, investors and collectors need to be more careful than ever to avoid buying fake gold. Counterfeit precious metals are popping up everywhere, so the last thing you want to do is spend your hard-earned cash on a doomed investment. If you own gold and you aren’t sure if it’s real, there are a few easy methods to confirm it. Testing gold is simple and can put an investor's mind at ease, and one easy method uses the facts we just learned about magnets. Read on to discover X different ways you can confirm that your purchase is genuine gold.
How to Test Gold Using Magnet Sticks
You can use a strong permanent ferromagnetic magnet to test if your item is pure gold. All you need is a magnetized material and the gold item in question. However, you do need to ensure that the magnet is strong so it can affect even gold alloy materials. Hold the magnet near to your gold, and watch carefully to see the reaction. If your gold is real, it shouldn’t move and the magnet should have no effect. If your magnet attracts the item, then it cannot be made from pure gold. However, it doesn’t necessarily mean the object is fake.
Unfortunately, the magnet test is not a fully reliable method to confirm if gold is genuine for two reasons. Firstly, fake gold can be made with other non-magnetic materials, such as stainless steel. In this case, the magnet would not attract your “gold” but that doesn’t mean it is real. Secondly, real gold can be mixed with ferromagnetic metals like iron, and therefore would attract the magnet. Using a magnet to test gold can be a very informative exercise, helpful in figuring out what materials and metals are contained within. However, to confirm whether an item is made from pure and genuine gold, you’ll need further tests.
How to Test Gold Using Nitric Acid
If you want to be completely certain about the validity of your gold metal, you can buy a professional testing kit. A nitric acid test contains everything you need to figure out the exact gold content of your item and discover if it is real or fake. For most investors, simpler tests will suffice and it isn’t necessary to purchase a gold testing kit. As well as magnets, you can complete a visual inspection of gold items, and test the density. These options require less commitment and can provide just as solid an answer. However, if you need to be certain that your gold is real, follow these instructions to test it using nitric acid.
1. Take a sharp tool and scratch your gold item in an inconspicuous location. You need to expose the layer of gold beneath the surface in order for the test to be accurate.
2. Add a drop of nitric acid to the scratched area. Make sure you use the correct bottle of acid for the gold karats your item is supposed to contain. Watch for a reaction; if the area turns green, your gold is fake. Genuine gold does not react with nitric acid at all. Reactions in other colors can indicate what metal your gold was mixed or plated with.
3. To test the purity of your gold, scratch it across the touchstone included in your kit. Then, add a drop of each karat nitric acid to the area, and watch for the reaction. Depending on which level of acid dissolved your gold, you can extrapolate the purity and number of karats.
Using nitric acid to test gold is a serious commitment, and if your item has a sentimental value you’ll probably want to avoid it. As you can see, the process involves scratching and therefore risks damage to the gold, so this test may be best left up to the professionals. If you want your gold acid tested but don’t want to do it yourself, take the item to your local jeweler.
Testing Gold with a Visual Inspection
Although it might seem a little too simple, a visual inspection can be a fairly effective way to confirm if gold is real. There are a number of clues you can find just by closely examining your gold item, and by finding these you can begin to figure out if your gold is genuine. If you’re looking at gold jewelry, look for a hallmark, a stamped number telling you the gold’s fineness. This figure, often found on clasps or the inner band of rings, might use a number from 1 to 999 or 0 to 24k. You can find the same digits stamped on gold coins and bullion, a grading system to state the quality.
You may need the help of a magnifying glass to spot this marking, which can be very small on some items. Additionally, very old pieces of jewelry or gold bullion may have worn away on the surface, obscuring the hallmark over time. This stamping procedure was only made mandatory in the year 2000, so it is also possible your gold was cast before this time. Another marking you might find on a piece of gold jewelry is letters indicating if the item is plated. The letters GP, GF, and GEP all signify that your gold is plated over another metal.
Testing the Density of Gold
The most accurate way you can test the validity of gold without risking damage or taking it to a professional jeweler is to test the density of the material. Pure gold has a density of 19.3g/ml, so this is the number you’re looking for. The density of 14 karat gold is around 12.9 g/ml, so any gold measuring outside the range of these two numbers is probably counterfeit. This method is also not 100% accurate as fake gold can also have a density similar to real gold, but most counterfeit gold won’t pass this test.
To begin with, drop your gold item in a large container of water. If the item sinks, meaning it is denser than the water, then you can continue to the next step. If the item floats at the top of the water or doesn’t sink all the way to the bottom, then it’s likely imitation gold or gold plated. Real gold also does not rust, so if you see a reaction with the water this is also an indication of counterfeiting. Should your gold pass this basic float test, you can move on to the more accurate density test. Follow these instructions to calculate the exact density of your gold:
1. Weigh your gold on an accurate scale. Record the figure in grams.
2. Take a graduated cylinder or measuring cup marked in either milliliters or cubic centimeters and fill it halfway with water. Place the container on a flat surface and record the water level.
3. Place your gold item inside the container with water, and record the new water level. Make sure you take the measurement using the same units as the first reading.
4. Subtract the initial measurement from the second to discover the difference in water level. This figure is the volume of your gold item. If you recorded these measurements in cubic centimeters, convert the figure to mL now.
5. Figure out the density of your gold by dividing the mass (the weight you recorded in grams) by the volume in mL. The resulting figure is the density of your gold item.
Now you know the density of your gold, you can make an informed guess as to its validity. While a result of 19.3 would happily confirm that you own pure gold, it isn’t the only result that could be genuine. If you own a gold alloy, the result you get would depend on the other metals used; they can be both more and less dense than genuine gold. Professional testing is the only way to be certain of gold’s purity, despite the fact that the density test is the most accurate you can easily complete at home.
Using Magnetism to Test Gold
Magnets are one of many different methods we can use to test if gold is real. Pure gold is not magnetic, so if your gold coin of jewelry is attracted to a magnet, unfortunately, it isn’t real. In fact, gold is actually diamagnetic, meaning it should slightly repel from a magnetic field. We have now discovered that a sole atom of gold can indeed be magnetized, but this remains impossible for everyday bullion. Next time you feel like putting your gold investment to the test, why not see how it reacts to a magnet?