How to Read a Diamond Tester

In this article, I will show you how to read a diamond tester. By following the tips, you can be able to use a diamond tester to determine the quality of a stone. If you have any doubts, feel free to ask a jeweler. Regardless of whether you are a beginner or a seasoned pro, knowing how to read a diamond tester will make the process much easier.

The basic way to determine the quality of a diamond is to observe its refractivity, which is the light’s ability to bounce back and forth. Diamonds have single-facet reflection, while other white stones have double-facets. Double-facet reflections in a diamond indicate that it is a diamond, while single-facet reflections are indicative of a white topaz or cubic zirconia.

Dependable Strategies

One of the greater dependable strategies for checking out for diamonds is to apply the diamond tester. It is a tool that detects and assesses diamonds and the gemstone recognized and moissanite by checking out the gemstone’s thermal and electric conductivity.

And if you are attempting to determine if the gems you\’re looking at are faux or real, a diamond tester could be the right system to apply. In this article, we’ll be sharing essential insights into what you want to realize approximately diamond testers and a way to use them.

What is a Diamond Tester?

A diamond tester can be defined as a small, portable device with a needle-like tip that is used to test the gemstones.

The needle-like tip is placed on the stone to be tested, and if the gemstone being tested is made of real diamonds, then the device would light up or sound a signal to indicate if the stone is genuine or not.

In the case of diamonds, warmth will by skip thru them withinside the diamond in another way like different apparently outstanding metals like glass or cubic zirconia, consequently the usage of diamond testers.

The tester will specify the fee of warmth switch thru the stones, telling you if the gemstone is authentic or fake. The diamond testers can also check for the stone’s electric conductivity, and that they paintings at the equal principle, trying out for the conductivity of power in preference to that of warmth.

In maximum cases, the diamond testers are utilized by the jewelers to decide the authenticity of the diamond rings, particularly in case you take rings to the jewelry save with the purpose of promoting or replacing it. Just to make certain that the gemstones are real, the diamond tester could be used.

How to Avoid Heating? 

Another important tip to follow is to avoid heating the stone too much during the testing process. If a stone is too hot, it will not register a diamond on the diamond tester. Cool the stone for 3 minutes before testing again. 

This will help ensure that the reading is consistent. In some cases, you may not be able to use the tester for a stone that is too small. For this reason, you should not use a diamond tester for a stone that is too small or too large.

Diamond testers, as stated above, will take correct measurements of the thermal conductivity of the diamonds/ gemstones examined to decide if the diamond is a simulated piece or a proper diamond. However, the diamond tester is not able to as it should take a look at or discover the artificial stone referred to as the moissanite as it stocks the equal thermal conductivity as diamonds.

The diamond tester, for example, the JEM-II, is designed with a steel alert device which is supposed to lessen a faux advantageous studying that might end result from the tester touching the metal, despite the fact that the stone isn\’t always a diamond or a few different sort of gemstone. The tester is calibrated for ease of use and correct readings with the metered volume, which suits stones of various sizes. It additionally has the ability to perceive stones that can be as small as 0.2ct. You’d join the tester to an AC adapter to be used indoors, however, the tester doesn’t include the AC adapter this is needed. You can be glad to recognize that given the small length of the tester, you could deliver it for your pocket.

There are different types of diamond testers, and it is best to use one with the highest resolution. A diamond tester is not a substitute for a jeweler. You can purchase a diamond tester at a jewelry store. In fact, the jewelry store’s prices can be a better indicator of the quality of a diamond than the one you buy. This article will show you how to read a diamond tester.

HMKIS Diamond Tester Pen, High Accuracy Jewelry Diamond Tester+ 60X Mini LED Magnifying, Professional Diamond Selector for Novice and Expert, Thermal Conductivity Meter

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  • [Easy to Use]: Real Diamond will Emits sounds and lights >=9.
  • [Intuitive Design]: Fake crystal, such as cubic zirconium ( CZ ), crystal, glass will be no sounds and lights <9.
  • [fast and safe ]: This diamond selector tester designed for quick, precise, and safe diamond testing. No harm to diamonds.
  • [Magnification]: 60X led Magnification with batteries ( Small microscope ). For Gems, Coins, Antiques, Stamps, Reading, Inspection etc.
  • [Service]: If you have any questions about use, please contact us. We will explain in detail. Professional equipment, the use method needs to learn slowly.

How to Use the Diamond Tester

  1. First, slide open the tester’s battery cover in the arrow’s direction, then insert a 9V battery. Then you have to slide the power switch until it gets to the Diamond option – in this position, the power bulb turns a solid red, while the adjacent bulb blinks green. Give it about 20 seconds more to allow the testing probe to heat up fully.
  2. You will know that the probe is heated up to the right temperature when the bulb starts to flash a solid green and make a short beep – this means that the probe is ready for use and the power-up cycle is complete.
  3. Also, make sure that the LED-level meter lights up in the 2nd column, and if it doesn’t, you’d want to adjust its volume control until the bar light in the second column lights up.

Cleaning and How to Use it? 

  1. You should always clean the tester and the probe thoroughly before you use them.

When ready to use the tester, remove its protective cap gently from the probe tip.

2. Next, hold up the diamond tester with your right hand’s index finger so that you touch its electricity-conducting panel on top of the diamond tester.

3. You’d want to press down the probe’s tip at the right angle on the stone. Just make sure not to press the tester on the stone at less than 90 degrees. Also, don’t apply too much force because it may bend or break the probe.

4. Once you’re ready to test, hold the testing probe settings with the left hand.

If you are testing for the loose stones, you should place them in the testing base – you can use one hand to secure the base.

As mentioned before, there are two types of diamonds: Type II and Type III. Type II diamonds are very rare and register as MOISSANITE on a diamond tester. Fortunately, most diamond testers are able to distinguish between a real diamond and a fake. If you are one of those lucky few, you can still tell the difference between a diamond and moissanite by using the standard two-part test.

Most Important

You should also know that when you test the same stone too many times, the stone will be heated up, and the results on the tester will tell you that the diamond is not a diamond even when it is. So, you shouldn’t test the stone too many times, and if it heats up, allow it to cool for about 3 minutes.

When done testing the diamonds, turn off the tester, and put it back in the case for storage. To ensure the best use of the tester in the long term, don’t expose the tester to humidity or dust because it has high-precision electrical circuits that would be damaged by the elements. Also, you should never open the other parts of the tester unless it is the battery compartment.

Another method to tell the difference between a diamond and Moissanite is to measure their thermal conductivity. Diamonds are the most expensive gemstones, so it is important to use a diamond tester to determine their quality. However, you should know that most basic testers cannot differentiate between a diamond and moissanite. This is because moissanite conducts heat differently than diamonds.

The next step is to use a jeweler’s loupe or a microscope to check the results. You will need to memorize the diamond plot and the laser inscription to read a diamond tester. As a beginner, I would recommend a jeweler’s loupe or microscope to make sure that you are seeing the correct value. If you are a professional, you can even learn to read a diamond tester by using a computer program.

Another method to determine if a diamond is real is to use a thermal conductivity tester. This type of tester uses a needle-like metal tip to determine the heat conductivity of a gemstone. This type of tester works on the principle that different types of gemstones conduct heat differently. 


This means that you can determine whether a diamond is natural or not by measuring the heat transfer rate. In addition, diamond testers use a sound signal to indicate whether a stone is real or fake.

Another method to verify the authenticity of a diamond is through the water test. To test for this, fill up a regular drinking glass with water. Place a loose diamond into the glass. If the gemstone sinks, it is a real diamond. Otherwise, it is a fake. Diamonds are very dense and the water does not reflect the light the same way as regular white diamonds. If the diamond floats, it is probably not a real diamond.