Whether you’re looking to buy or sell a diamond, you want to make sure it’s real – and not just a glittering imitation. You’ve probably heard of these small devices called diamond testers, which can supposedly tell the difference for you.
However, the question arises: Can diamond testers be fooled? The answer is plain and simple:
Yes, certain diamond testers can be fooled even if used properly. However, there are types of diamond testers that aren’t as easily tricked into believing a fake diamond is real.
In this article, we’ll cover everything you need to know about diamond testers – as well as some tips and tricks revolving around them. Without further ado, let’s jump in.
Never Heard About Diamond Testers?
As we step further into the 21st century, technology becomes more advanced – and it’s getting easier to make remarkably realistic imitations. Many of them could fool even the most competent expert without a gadget on hand to dig up the truth.
That is where diamond testers come in – They can tell the authentic gemstones from fake ones.
Since methods and materials advance rather quickly in this field, it’s probably best to use one of the latest diamond tester models. By doing so, you’ll ensure that you’re only getting accurate authenticity readings.
Due to their design, some jewelers refer to diamond testers as diamond testing pens.
When Should You Use A Diamond Tester?
If you’re purchasing, selling, repairing, or loaning diamond jewelry, you’ll likely come across one of these diamond testers.
- Purchasing: If you’re looking to buy a diamond, it’s worthwhile asking a jeweler to test the stones right in front of you. That way, you’ll ensure that you’re getting a good deal of authentic diamonds, not just some nice-looking fakes.
- Selling Or Loaning: If you want to sell or loan a diamond, the usual practice for the dealer would be to use one of these gadgets to test the authenticity of the diamond. That way, they can confirm its quality before they make an offer.
- Repairing: It’s worth getting the jeweler to test the repaired diamond in front of you when you come to pick it up. They should be glad to do it as part of their service, and it’ll give you peace of mind since diamond switching is a real risk.
Are Diamond Testers Trustworthy?
It’s not uncommon for labs to have diamond pen-type testers. It’s a great device that can help in separating certain imitations from genuine diamonds. But even this tester is only ever used with extreme caution.
Pen-type testers are divided into three types – thermal conductivity testers, electric conductivity testers, and multi-type testers. The earliest invented ones were thermal conductivity testers. They were supposedly allowing people to separate their diamonds from the most prominent imitation at that time, cubic zirconia.
In ideal conditions, when used properly, the testers would register an audio and visual signal denoting a “Fail” or “Pass” result for diamond authenticity.
Newer types of synthetic crystals, moissanite, certain rough rocks, and all lab-grown diamonds are capable of fooling thermal testers very easily.
These testers can designate other materials as diamond, even if these materials are composed of something entirely different. That’s because they exhibit relatively similar thermal conductivity properties to diamonds.
Electric conductivity testers and multi-testers are slightly more advanced and are generally made to distinguish diamonds from moissanite. The majority of diamonds have lower electrical conductivity than moissanite.
However, note that both mined and lab-grown diamonds could fall within the same range as moissanite on certain testers due to specific trace elements. Sensitivity and calibration on many of these devices can often change over time.
Despite this technology’s marketing, we’ve seen many moissanite samples pass as a diamond on few electrical conductivity testers.
We have also seen how many multi-tester and thermal tester readings can fluctuate as a result of minor changes in the surrounding conditions. These include accidental contacts with foreign surfaces or changes in pressure of the probe against the tested material.
There are several influencing factors that can disrupt a test’s performance, so miscalibration is definitely something to be wary of when you are using these gadgets.
Lab-grown diamonds, which are also made from pure carbon, will automatically register as “real diamonds” when tested with an electro-thermal conductivity tester. So, note that this test won’t differentiate synthetic diamonds from natural ones.
While we acknowledge diamond testers to be a helpful secondary test in gemology, more often than not, gemologists wouldn’t rely on the result of this test alone. Generally speaking, these will be used as screener tests for eliminating several known diamond imitations.
When performed properly, these kinds of tests are fine as supportive tests.
However, some sellers could use a few tricks to change a diamond tester’s readings purposely.
The sensitive internal wiring of many pen-type testers can sometimes change over time. They can also be dismantled and altered to reflect a higher sensitivity than recommended, meaning that testers have manual calibrations that can be manipulated in the wrong ways.
Some diamond sellers have discovered faults in certain diamond tester units that have allowed them to exploit the pressure differences of those testers to their advantage.
For instance, applying more or less pressure will occasionally affect the resulting verdict.
If you have no other means of testing a gemstone, properly using an electronic diamond tester is still much better than taking a wild guess. However, we don’t believe that these devices can be 100% consistent every single time.
For stones mounted onto jewelry, these pen-type testers might be the only applicable test in specific situations. Like any other test, there are always gemstones that can break the mold.
We can’t stress this enough: Several tests must be considered to avoid making any costly mistakes.
Each type of test has its own unique limitations that can lead to costly mistakes if overlooked. If you aren’t sure whether your tester readings are true, take the stone to a gemological lab – and people there will be able to give you the right answer.
How Do Diamond Testers Work?
Diamond testers use a needle placed on the top of the device to help detect whether a diamond is real. This needle operates with thermal conductivity to give you a reading.
Based on the rate at which heat travels through the gemstone you’re testing, the tester should be able to tell if the gem is genuine or not.
Others test the electrical conductivity of the gemstone. The same principles apply to these units – but they test electrical rather than thermal conductivity.
How To Use A Diamond Tester?
Diamond testers are rather easy to use once you’ve got the basics down. Be sure to read your model’s instructions to be able to interpret the readings properly.
Here are several handy tips to remember:
- Make sure that the gemstone is clean before testing it.
- Do not push the diamond tester tip down too hard onto the gemstone, as it can damage or break.
- Press the tip onto the gem at no less than a 90-degree angle.
- Make sure the tip’s touching the stone – and not the surrounding metal – if you are testing a stone set in a piece of jewelry.
- It’s best to use a neutral testing base when testing loose stones.
Learn More: What Happens When A Diamond Tester Beeps?
Useful Diamond Tester Features
If you’re looking to purchase a diamond tester, you should be aware of some beneficial add-on features you might want your chosen model to have.
The tips of diamond testers are very delicate – and they should be. That allows the testers to do their job properly. Look for a diamond tester that has a retractable tip, and it’ll ensure you apply the correct amount of pressure to the gemstone’s surface when testing.
That way, the tip protects itself from human error – and you won’t need to spend that much on replacements or repairs.
Quick To Reach Testing Temperature
Traditional diamond testers differentiate diamonds from other stones by measuring their thermal conductivity.
The tip of the tester heats up, and then you place it against the room temperature surface of the gemstone you want to test. Naturally, the heat is transferred from the warmer tester to the cooler surface.
And the tester gains thermal conductivity readings from this process.
So, if you were to test multiple stones in one sitting, you would want a tester that reaches – and returns to – testing temperature reliably and quickly. That way, previous readings won’t interfere with your future testing.
Ability To Differentiate Between Metal And Gemstones
Chances are you’re going to test gems that are already set in some kind of jewelry. So, you’ll want your diamond tester to be able to tell if you’ve accurately set the tip on the gemstone or accidentally placed it onto the metal.
If you buy a lower-quality diamond tester, it might not include the feature that warns you you’re testing the metal surrounding the gemstone. So, you’re likely to come up with false readings.
Accurate Across Varying Ambient Temperatures
Diamond testers work on the basis of testing thermal conductivity. That is how they tell the real diamonds from fake ones.
So, you don’t want your tester to get muddled up due to changing ambient temperatures. The higher the quality of the tester, the better its ability to cope with air temperature changes, ensuring more accurate results.
Battery Or Mains Powered
Cordless, battery-powered diamond testers give you more flexibility. However, you might want the option to hook your tester up the mains. Some models offer both opinions built-in, so keep an eye out for that when looking at product specifications.
Related Read: How Much Is A Diamond Tester?
Alternative Ways To Check Diamond Without Tester
Let’s talk about several at-home tests you can do to see if you’re holding a real diamond in the palm of your hand.
Hold the diamond directly in front of your mouth and breathe onto it. If the stone is foggy after more than a few seconds have gone by, then it’s probably a fake. Real diamonds disperse heat rapidly, and they tend to clear the fogginess immediately.
Grab a glass full of water and place your gemstone inside. Real diamonds are dense, meaning if the stone sinks all the way to the bottom of the glass, that would indicate that it’s genuine. If the gemstone floats or sinks a little, you’re dealing with a fake.
Draw a tiny dot on a piece of blank paper. Put your gemstone on top of the drawn dot, stand up, and look directly down onto the dot through the stone. As real diamonds refract light, your stone should refract the reflection of the dot.
While these simple tricks could tell you if your gemstone is the real deal or just a glittering fake, it’s worth investing in a proper diamond tester that will ensure you get more accurate readings.
Let us answer the question, “Can diamond testers be fooled” once and for all:
While pen-type testers provide a great secondary test, gemologists wouldn’t rely solely on them, as these testers can be fooled. They’ve never given confidence in the consistency of the results.
So, these instruments are used as screener tests for the elimination of few known imitations. You should use a diamond tester if you want to buy, sell, loan or repair your diamond, though.
Diamond testers work either by checking the thermal conductivity or electrical conductivity of the gemstone. In order to get accurate readings when using a diamond tester, make sure you clean your diamond, use the appropriate amount of pressure on the tip, and press the device’s tip at a 90-degree angle.
Diamond testers can have several features like a retractable tip or the ability to tell between the metal and the gemstone. Be sure to check if your unit has some of these helpful features.
If you’re in doubt regarding your tester’s reading, bring your gemstone to a gemological lab for a more thorough examination.
Read Also: Is IGI As Good As GIA?