Diamond Tester: How Does It Work?

A diamond is a precious piece whose originality has to be tested, and whether diamonds are fake or not can be revealed in many ways. One of the fastest and most accurate ways to do this is to use a device for testing diamonds called a “diamond tester”.

The diamond tester is a very useful device that can be carried in a pocket. These devices contain a small needle to be placed on the stone to be tested. If the diamond under test is not fake, this will be reflected on the screen of the device; at the same time, the device can emit a vocal signal. The way diamond testers work is that heat passes through the stone, indicating a statement about the authenticity of the diamond. Also, some devices use electrical conductivity. Typically, these devices attributed as the most reliable diamond testers.

In a conventional diamond tester, the metal tip is first heated and then applied to the cold surface of the diamond. As a result, heat transfer is provided. The heated metal tip of the device used for the test heats the diamond. Thus, a match is achieved by making a reading between the diamond and the tester. As a result, it is revealed whether the diamond is a real diamond.

On the other hand, nowadays the difference between fake diamonds and real diamonds have become much smaller as a result of very good imitation. Recently emerged testers have a different system for comparing the properties of diamonds and their imitations. These testers try to reveal different characteristics in today’s imitations and simulations.

How Does a Diamond Tester Work?

Diamond testers function based on a different operating principle based on the fact that different gemstones conduct heat differently. Depending on the type of stone, heat passes through the stones differently; For example, the transfer of heat takes place differently between a diamond and cubic zirconia.

Through diamond tester devices, the level of heat passing through the stone is determined and the level of reality is revealed. In some tests, it is the electrical conductivity used in the test phase – the underlying principle is the same; the difference is that electricity is used, not just heat.

Portable diamond testers are very useful in situations where the authenticity of a diamond is required to be learned, as they are functional and portable. At the same time, diamond testers are frequently preferred as they are very meticulous in reaching the results and save time and effort.

Types of Diamond Testers: Electric and Heat

If you are planning to buy a diamond tester, you may not know enough about which type of diamond tester is better. Recent research has proven that diamond testers that show results through electrical conductivity are much more successful than diamond testers that provide conductivity through heat.

Although these devices cost a higher amount than devices that use thermal conductivity, they are preferred and should be more preferred due to their more reliable results. By contrast, test devices that use heat are much more affordable; however, the accuracy and precision of its results are lower than devices using electrical conductivity and as a result, may not give very good results.

If you are professionally dealing with diamonds and you will be testing the authenticity of multiple diamonds in one day, the recommended device is a device that uses electrical conductivity. This is because a type of “fake diamond” called moissanite can be detected as a fake, using only electricity. Moissanites are dazzling just like diamonds, but they are not diamonds; their structure is different from a diamond. With the development of technology, many test models have proven reliable in the market age, but using an electrical conductivity tester is the option that brings you closer to reality.

How Reliable Are Diamond Testers?

When you decide to buy a diamond tester, there are a few things to consider. First, know that the device you are using must manifest through the different electrical conductivity between moissanite and diamond. However, the latest devices consist of combining heat and electrical testing to achieve the highest accuracy results.

Another advantage is that these devices detect and signal when the stone is not touched accidentally, for example, if the metal setting is touched. In a situation where the tester does not recognize the metal, even if the diamond is fake, touching the setting by mistake may give a misleading result as the diamond is real. Therefore, using the device is as important as owning it for them to deliver reliable results.

Diamond testers are among the most common and accurate tools for determining the authenticity of a diamond. However, you should know that there is a possibility that testers using thermal conductivity might confuse moissanite with diamond. This is because how both stones conduct heat are very similar. This is a big problem when determining originality. To solve this problem, a device that uses electrical conductivity, not thermal conductivity, is used; Because how moissanite and diamond to conduct electricity is quite different from each other.

The system in a multi-tester is that this device combines the thermal conductivity test with the electrical conductivity test. Because most diamond multi-testers work in this way, one of the most important features to look for when choosing a diamond tester is that the multi-tester has a system that alerts you when it touches a metal fork instead of a precious stone. The reason this criterion is so important is that a metal nail is considered a diamond by a device without warning related metal.

The Relationship Between Diamond Testers and Ultra Violet Light

Some of the diamond tester models have a UV light and raised an expectation that UV light could be used to test diamonds, but this belief is not true. It is not possible to tell the difference between diamonds and other stones such as moissanite through UV light. A useful thing to know is that diamonds are randomly fluorescent, and if the result is the same response to all the stones that make up a ring or your diamond brooch, whether they are fluorescent or not, then they are probably not diamonds. If some fluoresce while others do not, then they are more likely to be diamonds.

UV light, however, points out the possibility of starting when natural diamonds and synthetic diamonds are compared. For examining diamond ‘parcels’, there is a need for a long wave UV lamp AND a short wave UV light. So, you should see stones in a dark room and on a background in the color of black. Natural colorless diamonds, almost 40% fluorescent, often fluoresce more under long-wave than under short wave. Some synthetic diamonds react in the opposite direction; fluorescence is weak under longwave and strong under short wave.

Diamond Fluorescence

Therefore, in the case of purchasing loose diamonds, diamonds should be examined under UV light to assess the possible mix of ‘natural’ and ‘synthetic’. On the other hand, checking a diamond under UV light may not mean anything to you. This is because such information is suitable for interpretation by jewelry experts or professional diamond retailers. So, a non-professional jeweler may not be able to sharpen these and not be an expert in this field.

Lab Diamonds and Diamond Test

Can a diamond test be applied to carbon lab diamonds to assess their authenticity, just like natural diamonds? The answer to this question is in some cases, yes and in some cases no. Testing diamonds for these diamonds takes place in several ways. Knowing which tests to apply to synthetic diamonds, which tests they will pass, and which ones will be moved is as important as knowing about real diamonds. Carbon lab diamonds can pass tests for their physical and chemical properties, but when these diamonds are evaluated with the eyes of an expert, these differences become quite obvious.

Natural and laboratory-grown diamonds have the same crystal structures; that is, their chemical composition is similar to each other. As such, the terms “synthetic diamonds” or “manufactured diamonds” are not used to refer to the diamonds themselves. So, chemically speaking, these lab diamonds are also real diamonds. The designations “synthetic” and “manufactured” refer to the laboratory-based manufacturing process.

The GIA has detected a lot of synthetic diamonds fraudulently mixed with natural diamonds. And making these definitions is not as difficult as it seems, it is easy. A few signs are tasked with showing the lower value of carbon lab diamonds. These tests are done for inclusion and clarity evaluation. Most lab-grown diamonds are readily generated synthetically.

At the same time, the other feature that gives away laboratory diamonds is inclusions. There is a metal solution that is used to help lab diamonds grow, and this indicates metallic inclusions in carbon lab diamonds. These inclusions are visible when viewed at 10 times magnification and become quite obvious even if a magnifying glass is used and a cursory examination is performed.

Unveiling Fakes

A thermal conductivity probe or a “diamond tester” is used to accurately identify fake diamonds. As diamonds are highly effective heat conductors, they rapidly absorb and distribute the heat applied to their surface. A tester for electrical conductivity also provides a useful measure. While many fake diamonds do not conduct electricity well, diamonds conduct electricity very well.

Finally, sets that have high profile weight diamonds apart from other gems. Scales produced for weighing carats may differ slightly between stones in terms of weight. If a stone differs too much, it indicates that the stone is not a real diamond, indicates that it is synthetic.

Well, the question arises of what all this means for synthetic diamonds. The value of a diamond depends on its worth and level of perception in each case. It is revealed by opinion polls and diamond price points that synthetic diamonds are not just as sought after and valuable as natural diamonds. Of course, diamonds are seen as an eternal expression of love. So many people are hesitant to trust lab-made diamonds.

Lab-grown Diamond Circle Necklace


The story of no synthetic diamond is the same as the story of a natural diamond, and so as a symbol tasked with expressing something timeless, the diamond should also be timeless. Most people are hesitant about the production journey of a synthetically created diamond. Therefore, a synthetic diamond has not yet been able to fully replace diamonds, the timeless symbol of love. When choosing between natural diamonds and synthetic diamonds, the problem in customers’ minds is exactly the problem of trust. If you doubt the authenticity of your diamonds, have them checked by a professional diamond analysis.

Top 5 Testers That Can Be Used To Find Out If Your Diamonds Are Real

If you are in a rush and fair need to discover out what the most excellent precious stone analyzers are, at that point, it is recommended “Presidium Adamas jewel analyzers” as the finest. A part of your gems devotees cherishes to know their stone’s quality. Whether it is the unobtrusive contrasts between a moissanite and a precious stone or cubic zirconia and sapphire, so, you must know the esteem of contributing to a versatile and exact jewel analyzer. Well, whether you’re a tenderfoot who’s inquisitive almost gemstones, or an expert who values exactness and consistency, my audits of the best 5 best precious stone analyzers are here to assist.

Diamond testers are great gadgets that are compact electronic machines ordinarily claimed by jewelers. They are utilized to affirm the validity of jewels. The gadget itself is convenient and handheld, outlined like a writer to carry around in your stash. The gadgets will frequently incorporate a modest needle-shaped tip simply put on the stone. After that, one a kind sound or visual signal will clarify the clarity of the stone. Most analyzers’ capacities utilizing the nuts and bolts of warm conductivity. Through different substances, heat conduction varies, and jewels have their special properties of warm conduction. Some diamond testers completely depend on electrical conductivity rather than heat conductivity.

Before we list the brand that you should prefer, we can take into the criteria brand, price, ease of handling, and conductivity. So, these criteria are explained below:

Brand and Price

There are diverse models that you can use as a diamond tester. However, the brand of Presidium is very prevalent within the gems advertise. In any case, there is no need fair obtrusively recommend particular brands. For this reason, you ought to continuously investigate for reasonable, agent data of brands and items that are all chosen on their intrinsic quality. Moreover, you ought to be prepared to spend on a range of price labels when searching for precious stone testers, from reasonable to marginally more burdening on the wallet.

Presidium Diamond Tester

Ease of Handling

In case you are a beginner, you may need an unassuming and comfortable tester to utilize so you will not squander time on setup and examination. Most gadgets have both sound and visual signals and these make them prepared for prompt utilize. So, in a situation that you are somebody who visits busy barters rather than being the examiner, it is best to go for convenient and pocket-sized testers.


The two sorts of conduction utilized by precious stone testers are based on electricity or heat. However, it can be asked which is more prevalent than the other. For both of them, it can be said that electric conduction testers are a parcel superior to those that utilize warm conduction. Whereas they are regularly more costly, you oversee to induce more precise comes about. On the other hand, heat testers, are more budget-friendly, and so, they are valuable for on-budget clients. The most known and the best diamond testers as follows: 

The Presidium Adamas Diamond Tester

“The Presidium Adamas” is a brand that is accurate on precious stones as modest as 0.02 carats. It moreover comes with an extra smaller scale tip for a 0.01-carat precision range. You can certainly see this in most activities and gems stores. The test tips are movable, meaning you get to supplant the tip on the off chance that it is harmed or worn out. This highlight is helpful since investing in modern analyzers could be a part more exorbitant than displacing the tip.

Considering its capacity to test precious stones, moissanite, and numerous more stones alike, this gadget appears to be very valuable. The tip is additionally thermoelectric and employments USB charging. Hence, the gadget is simple to transport and charge anyplace. Another striking include is the inside memory chip with a test amount of up to 500. Hence, Adamas is an ideal choice in case you can sacrifice tall sums.

Its Pros:

  • Portable and Lightweight
  • Accurate Results
  • Double power supply
  • Internal memory chip

Its Cons:

  • It more cost

To create the ultimate choice is almost your choice. Fair keep in mind the essential highlights and your needs, at that point picking the perfect item ought to be simple. In this stage, you ought to center on pricing, accuracy, warmup time, toughness, and ease of use for the best diamond testers.

This tester is one of the foremost effortless testers. It feels comfortable amid taking care of. Also, it has high quality. Adamas is suggested for experts like professional jewelers. That said, in case the device appears as well overwhelming for you, at that point any of the low- to mid-tier alternatives recorded above ought to be fair fine as well.

Presidium II Diamond Tester

The Presidium’s Gem Tester II comes in a lighter, more durable, and more compact design compared to the other Presidium Adamas model. This tester is often used by professionals and therefore this product will appeal to them more than novices. Although this tester has thermoelectric property, its results are primarily based on heat. Although heat is less accurate than electricity, it still delivers fast and accurate results on a clear analog display. It works on moissanite, diamond, and 16 other stones, thus offering a wide variety of tests.

This new design has built-in calibrations that are interchangeable based on whether you are both inside and outside. At the same time, this tester is the thinnest retractable tip device available on the diamond tester market. Its test stones are as small as 0.02 carats, but it is a wise idea to invest in Presidium Gem Tester II as it gives accurate results in very little waiting time.

Its Pros:

  • Stones can be both polished and non-polished
  • The consistent level is high
  • The use of AA batteries
  • Suitable for use on smaller stones

Its Cons:

  • Not budget-friendly

StillCool Diamond Tester

You completely will appreciate testing StillCool’s gadget since it is so reasonable and versatile. You fair rapidly utilize it to choose honest to goodness jewels out of the fakes, without requiring to spend as well much. It can be utilized on all stones but will as it were signify genuine precious stones in the test process.

The tester is battery powered and therefore easy to use. It also has simple functionality. This is because it has both audible and visual stimuli as to whether the stone is original or not. This device can test both bulky and compact shaped diamonds and uses a primary switch to get started. Those who will use the device do not need to quickly study the manual to understand what the green light means. Still, most beginners will find their detailed instructions quite useful to understand how to operate the tester. Therefore, StillCool’s device is a good option for low budget jewelers.

Its Pros:

  • Portable
  • Budget-friendly
  • Has audible and visual indicators
  • Ideal for beginners

Its Cons:

  • It does not include batteries
  • It has a lower accuracy
  • It only functions on diamonds

GemOro Diamond Tester

GemOro has launched an Ultratester to the market. This device is among the most accurate and sensitive devices you can get. Thanks to its patented structure, it is very easy to use and can be carried easily. It is also very stylish and the hand design is ergonomic. Functionally versatile, this device can test multiple gemstones in addition to diamonds.

The tip shines and has a simple green and red color system to indicate whether the stone is real or not. Also, the alert is audible and you get an LED diamond illuminator for clear vision. With the device, it is possible to easily detect diamonds, white sapphires, metals, and moissanite. The probe is very robust, protected by a spring-loaded cover. The warm-up time between tests is also only 10 seconds. The auto shut-off function when not in use also helps save battery. Therefore, GemOro has a user-friendly design and is in a good position among other testers with these features and quality.

Its Pros:

  • Quickly warms
  • Solid and covered tip
  • has a comfortable grip
  • has good quality

Its Cons:

  • The indicator may malfunction
  • It costs high amounts

Tekco Plus Diamond Tester

This diamond tester is not as expensive as other tester options. It appears as a mid-range product among diamond testers. Consequently, although it does not qualify as a famous brand that is well known around the world, it is of substantial quality and therefore makes a smart test device to invest in.

This diamond tester is still one of the most accurate tools within reach. Although not of high quality, it is successful in detecting diamonds, moissanite, and even some metals other than gold. However, many low-priced tests find that stones below 0.25 carats do not reliably and precisely check. For this reason, TekcoPlus still delivers accurate results among these devices. However, it also has a negative side. The downside is the shorter battery time and half a minute warm-up time. If you do not want a device with a lot of features but want a device with high accuracy, you can trust TekcoPlus.

Its Pros:

  • Accurate results
  • Affordable price
  • Clear display screen

Its Cons:

  • Generic brand

5 Home Tests to Tell Whether Your Diamond Is Real or Not

Whether a diamond is genuine is the most crucial issue in purchasing a diamond. Well, if you do not have a tester but still need to check if your diamond is genuine, would you like to know how to find out? There are some tests done at home, on your own, to check if a diamond is genuine, without the need for a professional jeweler.

Diamonds have a few “fake” equivalents that can effortlessly be befuddled with genuine precious stones – common stones that have a solid likeness to jewel, colorless sapphire, colorless topaz, and colorless zircon. There are too lab-created diamonds like yttrium aluminum garnet, manufactured cubic zirconia, and gadolinium gallium garnet engineered moissanite that looks like real diamonds to the average individual. This likely causes that you are curious about how to tell on the off chance that a diamond is real if there are as well numerous comparative.

Experts recommend that you do your part. “The biggest misconception is to think that there is only one kind of ‘fake’ because there are many imitations of diamonds in the jewelry market today, not just one or two. Of course, you want your stone to stand the test of time. Therefore, it is advisable to consult a reputable jeweler to question whether a diamond is genuine. However, if you want to do this yourself, you can try at home to find out if a diamond is fake. There are five simple home tests.

Test Using Fog to Distinguish Real Diamond from Fake Diamond

To find out if your diamond is fake, bring your jewelry close to your mouth and mist it with your breath as if it were a mirror. If the diamond remains cloudy for a few seconds, it is probably fake. If it is a real diamond, the diamond does not fog easily as the condensate does not stick to the surface.

Test Using Water to Distinguish Real Diamond from Fake Diamond

This method is one of the easiest to try at home. To do the water test, take a glass and put water in it. The type of water you put in is not important. Drop your diamond into the glass you filled. Because diamonds have a high density, they will sink to the bottom when placed in water. So if the diamond is floating on the top or in the middle of the glass, the diamond is fake. Physics will give you the right answer.

Test Using a Magnifying Glass to Distinguish Real Diamond from Fake Diamond

Another home test to use to determine if your diamond is genuine uses a magnifying glass. Hold a magnifying glass at the diamond and look at your diamond through the glass. Look for flaws in the stone If you can’t find any flaws, the diamond is most likely fake. Most real diamonds have imperfections called inclusions. There are diamonds out there that are sold flawlessly, but these diamonds are either very expensive or lab-created diamonds.

Test Using Black Light to Distinguish Real Diamond from Fake Diamond

For this test, you need a black light. Once you have your diamond in hand, turn off the lights in your location, and put the diamond in front of the black light. Most diamonds show blue fluorescence under black light and hence a blue color. The blue light means the diamond is real. If you do not see the blue color and instead see a slightly green, yellow, or gray fluorescence, this usually means the gem is fake. However, you should know that this test is not absolute and not all real diamonds will show a blue fluorescence.

Test Using a Loupe to Distinguish Real Diamond from Fake Diamond

Jewelers use a jeweler’s lens to see small details up close. A loupe and magnifying glass are therefore different. The difference between them is that the loupe does not have a handle and its lens frame is a bit more tapered. Jewelers often use magnifiers when examining diamonds for grade and clarity.

First, seek for inclusions using the loupe. Mined diamonds often have minor and natural defects that indicate the diamond is real. Next, check for minor mineral spots or color changes. If there are little color changes and spots on the diamond, then the diamond is most likely real. However, keep in mind that some diamonds are flawless. If there are no flaws, that does not necessarily mean you are dealing with a fake diamond. It means that there are excellent diamonds that are rarely found. Although most real diamonds often appear to have imperfections, this method is not very reliable in making the final decision.

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Savaş Ateş

My wife has a huge interest in diamonds. After she asked me a lot of questions about it, I found myself in diamonds. I made a lot of research on it. I read books. I visited manufacturers. I visited the stores. I have made good friends in that field. I want to share my experiences with you.

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