Dealing in diamonds requires the ability to test for authenticity, and the simplest and most reliable way to check if a diamond is real or not is to use a diamond tester. Electronic diamond testers are affordable instruments that find favour with gemologists, jewellers, pawnshop owners, and consumers alike. These testers measure the physical properties of stones and provide users with accurate information about their authenticity. This is normally in the form of an audible sound. Some models include LED indicators as well.
Most models that sell on eBay are lightweight and many include carry cases. Some offer calibration functionality to work with different sized diamonds. Most electronic diamond testers draw power through replaceable batteries, such as AAA or AA. If you have to test precious metals, you can look for a diamond tester that is part of a precious metal testing kit. Such kits include silver, gold, and platinum testing acids as well. Give yourself the ability to tell a real diamond from one that is not and breathe easy.