Instrument to test diamonds

Choose based on accuracy, portability, compatibility with other stones, and budget. For casual use, consider a pen-style diamond tester—these often pair a tester with a built-in magnifier, like a 60X jeweller's loupe, which helps you verify details up close. For professionals or heavy users, opt for a high-precision portable electronic detector that supports multiple stones and quick verification. Also check that the brand offers a practical kit, since some models bundle useful extras and use readily available batteries.

The testing method used by the instrument is the most complex feature. Thermal conductivity testing is common and must be interpreted with care because it can be fooled by moissanite or synthetic stones. Some devices combine methods for better accuracy, so look for multi-method testers. Also consider how readings are displayed and how easy calibration is.

If you're a beginner, a simple pen tester with a magnifier is ideal for quick checks. If you're a professional or frequent seller, you need a high-precision detector that works across stones. If you regularly test stones like jade or rubies, pick a device that supports multiple gemstones.

Maintain the device by keeping the probe clean and dry, and store it in a dry place. Replace batteries when needed, and note that some models include a 9V battery. Calibrate as recommended by the manufacturer to ensure accurate readings. Ensure the instrument is compatible with the stones you test, including moissanite, to avoid misidentification.

Yes, but reliability varies between models; choose a tester labeled for moissanite for higher accuracy. Some testers are specifically designed to distinguish diamonds from moissanite, while others test a broader range of gemstones. If you frequently handle different stones, select a multi-stone tester to simplify verification.

Look for functional, budget-friendly brands that specialize in diamond testers and gemstone testers. Prioritize models described as high-accuracy or multi-stone testers and check for included accessories like a built-in magnifier and batteries. Choosing a reliable brand with good support helps ensure long-term accuracy and peace of mind.