Are Diamond Testers Accurate?

When delving into the world of diamonds, one often wonders about the tools used in the identification process. At the heart of this curiosity is the diamond tester. It's a device designed to help identify genuine diamonds. But how reliable are they? Let's explore the intricacies of diamond testers and their accuracy.

Types of Diamond Testers

Understanding diamond testers starts with recognizing the various types:

  • Thermal Conductivity Testers: Diamonds have a unique property—they disperse heat differently than other stones. These testers rely on this property to identify diamonds.
  • Electrical Conductivity Testers: Some diamonds, notably those with boron impurities, conduct electricity. This tester capitalizes on that fact.
  • Ultraviolet Light Testers: Diamonds may fluoresce under ultraviolet light. This tester uses that fluorescence to spot diamonds.
  • Combined Testers: These are the latest advancements, combining multiple testing methods to enhance accuracy.

Factors Affecting Accuracy

Even the best tools have their limitations. Here's what can influence the accuracy of a diamond tester:

  • Calibration: Just like any precision instrument, diamond testers require proper calibration to ensure accurate results.
  • Battery Life: A waning battery can compromise the tester's accuracy.
  • Gemstone Temperature: The stone's temperature can influence the reading. It's best to let a stone acclimate to room temperature before testing.
  • Presence of Moissanite: This gemstone has properties very similar to diamonds, often leading to false positives.
  • User Experience: The accuracy often hinges on the user's skill and experience in handling the tester.

Limitations of Diamond Testers

While diamond testers are invaluable tools, they do come with constraints:

Recognizing the possibility of false positives and negatives.

  • The challenges they face in distinguishing between diamonds and similar gems.
  • The inevitable human errors that might creep in during testing.

Compared to Professional Appraisals

Nothing truly matches the precision of a professional appraisal. Here's why:

  • Laboratory Testing: Professionals at establishments like Vivian Jewelers use advanced equipment, going beyond the capabilities of standard diamond testers.
  • Expertise and Experience: The seasoned eyes of a gemologist can often spot nuances missed by electronic devices.
  • Certifications and Guarantees: When you get your diamond appraised by a professional, it often comes with a certification, offering peace of mind.

Tips for Accurate Testing

To make the most of your diamond tester:

  • Maintain it properly, ensuring its longevity and accuracy.
  • Always wait a bit between tests, especially if the stone is cold or hot.
  • Understand the limitations of your specific tester model.

If ever in doubt, it's wise to consult professionals, like our experts at Vivian Jewelers.


Diamond testers are undeniably helpful, serving as an excellent preliminary testing tool. However, for complete certainty, especially for valuable or heirloom pieces, always consider coupling it with a professional appraisal. At Vivian Jewelers, we're here to assist, ensuring you're always confident in your diamond's authenticity.

For those keen on diving deeper, we recommend a few trusted publications on diamond testing. Reach out to our team at Vivian Jewelers, and we'd be more than happy to guide you.

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