Last updated on December 27, 2022
There are many methods to tell if a diamond is real or fake, but most of them are not 100% reliable. However, using a diamond tester is one of the fastest and surest ways to tell if you deal with a real stone. But how does a diamond tester work, and what do we need to consider to get accurate test results?
What Is a Diamond Tester?
A diamond tester is a portable device used to check the authenticity of diamonds and test materials for their thermal and electrical conductivity. It can accurately indicate if the stone is a real diamond based on the gem’s physical properties.
Depending on the principle the tester utilizes, there are devices that measure the thermal conductivity or electrical conductivity of the stone and multi-testers that combine both methods. Diamond testers that use thermal conductivity measure the amount and speed with which heat travels through the stone, while the ones using electrical conductivity measure the amount and speed through which electricity travels through the gem.
Diamond testers’ principle of operation is based on the fact that each type of gemstone has its chemical structure, meaning each of them conducts heat and electricity differently. In other words, heat or electricity will pass through an authentic diamond in a different way than it would through cubic zirconia, for example.
To test if a diamond is real, you will need to place the tip of the tester on the stone’s surface and detect the rate at which heat or electricity moves through the gem. If the diamond is genuine, the device will indicate that on the display and give a sound signal.
What Type of Diamond Tester Is Better?
Diamond testers are probably the most accurate and reliable tools to check the authenticity of a diamond. However, it is worth mentioning that electrical conductivity diamond testers and multi-testers are much better than thermal conductivity testers. Although they are higher in price, they are much more accurate.
Diamond testers that measure only the thermal conductivity of a stone cannot tell a real diamond from moissanite as these two stones are very similar when it comes to interaction with heat. To get accurate results, you will need a tester that measures the electrical conductivity of a stone or combines both aspects because diamonds and moissanites conduct electricity differently.
Technology is advancing, and there are many accurate models on the market; however, to choose the best diamond tester, you may want to consider some aspects. The best models have a metal detector that signals if you touch a part of the setting instead of a gemstone. This is important because metal will register as diamond on most diamond testers that lack the metal detector feature.
In case you are buying a thermal conductivity diamond tester, make sure it will test accurately across a range of different room temperatures. Also, a good tester should not warm up fast and have little or no lag time between tests.
Do Lab-Grown Diamonds Pass a Diamond Tester?
Diamond testers help to separate real diamonds from anything else. Lab-grown diamonds are identical to natural ones in their crystal structure, chemical composition and physical properties. This means they also have the same thermal and electrical conductivity properties, so lab-grown diamonds test positive on any type of diamond tester.
However, it is worth mentioning that a diamond tester will not help identify if a diamond is created or natural. Other methods are used to distinguish between them. These methods include detecting colour zoning, strain patterns, inclusions, fluorescence, etc.
Although synthetic diamonds have the same crystal structure and chemical composition as natural ones and pass a diamond tester, the diamond growing process leaves unique features in the finished products. These features help tell synthetic diamonds apart from natural ones and even identify which method has been used to grow the diamond.
Featured image: Nut Korpsrisawat / Shutterstock
