At Goldsmith Jewelers, we understand the importance of authenticity and quality in every gemstone. With our long-standing history in the jewelry industry, we’re here to share our expertise on how to use a diamond tester, ensuring that you can confidently identify the real gems from the imitations.

Understanding Diamond Testers

What is a Diamond Tester?

A diamond tester is an essential tool for determining whether a stone is a real diamond. It works by measuring thermal or electrical conductivity, attributes that diamonds uniquely possess. There are two main types: thermal conductivity testers and electrical conductivity testers. While these tools are incredibly useful, they do have limitations, which we’ll discuss later.

Preparation for Testing

Getting Ready

Before testing, it’s crucial to clean the diamond thoroughly, as residues can affect the results. Also, make sure your tester is correctly calibrated – a step that’s vital for accurate readings.

How to Use a Diamond Tester

Step-by-Step Guide


  • Power On: Switch on the tester and give it a moment to warm up.
  • Clean Contact: Ensure the diamond’s surface is clean.
  • Proper Placement: Gently place the tester’s probe on the diamond.
  • Read the Results: Observe the readings to determine if the stone is a real diamond.

Interpreting Results

The tester will indicate whether the stone is a diamond or another type of gemstone. If you’re unsure about the readings, remember that our experienced staff at Goldsmith Jewelers are always here to help.

Limitations and Considerations

While diamond testers are reliable, they’re not infallible. Factors like extreme temperatures can affect readings. For complete assurance, we recommend a professional appraisal – a service we’re proud to offer at Goldsmith Jewelers.

Maintenance and Care for Diamond Testers

Like all precision instruments, diamond testers require proper care. Store them in a safe place and handle them delicately to ensure their longevity and accuracy.


Understanding how to use a diamond tester is part of being a well-informed jewelry enthusiast or professional. At Goldsmith Jewelers, we’re committed to providing not just high-quality jewelry but also the knowledge to appreciate and care for it.


Here, we address some common queries. And for more questions, don’t hesitate to contact us or make an appointment with our experts.


For further information on diamond testing and our range of services, visit our blog.