• Jewelry Fashion
  • Shopping & Selling Tips
  • Jewelry Care
  • Gemstones
  • Metals
  • Materials
  • Jewelry Basics

Home » Jewelry Shopping & Selling Tips »

How Do Diamond Testers Work and Are They Reliable?

There are a lot of ways to tell whether a diamond is real or fake. The problem is that most of these methods are not 100% reliable. Using a diamond tester, however, is one of the surest and fastest ways to check if you have an original diamond.

What Are Diamond Testers?

A diamond tester is a portable device that you can put in your pocket. The tester has a small, needle-like tip that needs to be placed on the stone tested. If the diamond is real, the device indicates that on its display or with a sound signal.

A diamond tester checking a ring stone for authenticity

How Diamond Testers Work

Diamond testers’ principle of operation is based on the fact that different gemstones conduct heat differently. Heat will pass through a diamond in a different way than it would through cubic zirconia or glass.

A diamond tester will detect the rate at which heat moves through the stone and will tell you whether it is a real diamond.

There are also testers that use electrical conductivity to test stones – they are based on a similar principle, but they use electricity instead of heat.

What Are Diamond Testers Used For?

Diamond testers are used by jewelers all the time to check the authenticity of diamonds.

If you bring in your diamond with the intention to sell it or exchange it for another one, the jeweler will want to make sure your stone is real as this is not always obvious.

Before repairing a piece of jewelry, it is also critical for a jeweler to know what the stone in the setting is since different gemstones tolerate heat, pressure and stress differently.

As a customer, it is a good idea to make the person who repaired your diamond jewelry test the stones in front of you when you are receiving them.

And if you are not sure that the gemstone you have is a real diamond, you can always go to a jewelry store and ask to have your stone tested.

How Reliable Are Diamond Testers?

Diamond testers are one of the most accurate tools to check a diamond for authenticity.

However, you should know that testers that rely on thermal conductivity can mistake a moissanite for a diamond because these two stones are very similar in the way they conduct heat.

This problem is solved by using a device that uses electrical conductivity to test stones – diamonds and moissanites conduct electricity differently.

What Makes a Good Diamond Tester?

If you’ve decided that you want to buy a diamond tester, there are several things you should be looking for.

First, make sure that the device uses electrical conductivity in order to tell a diamond from a moissanite. The latest models available on the market combine heat/electricity testing for greater accuracy.

Another good feature is having a metal detector that signals if you accidentally touch part of the metal setting instead of the stone.

If your tester doesn’t recognize metal, it can indicate that you are holding a real diamond when you unknowingly touch the setting, even if the diamond itself is fake.

Where to Buy Genuine Diamonds?

We recommend James Allen (read review) because you can take a 360-degree look at any diamond before buying it. 

We also recommend Blue Nile and Ross-Simons.

Disclosure: Some of the links on our site may help us earn affiliate commissions from advertisers. As an Amazon Associate, we may earn from qualifying purchases. Learn more

Read Next

  • Should You Buy Used Jewelry?
  • Diamond Inclusions: Complete Guide
  • What Are Black Diamonds and Should You Buy Them?
More: Diamonds Gemstones


Related Articles
  • Diamant
    What Are Diamond Black Spots and Can They Be Removed?
  • 1109-diamond-feathers
    What Are Diamond Feathers and How Do They Affect Clarity?
  • diamond-ring
    Diamond Accents: What They Are and How to Buy Them
  • Shiny bright diamond
    What Are Laser-Drilled Diamonds and Are They a Good Choice?
Additional Resources
  • Guide to Buying Diamond Testers
  • All About Diamond Testers
  • How to Use the Diamond Tester

Popular Topics
• Rings
• Necklaces
• Bracelets
• Earrings
• Diamonds
• Pearls
• Gemstones
• Gold Jewelry
• Silver Jewelry
• Platinum Jewelry

  • More Jewelry Topics
    • How to Choose Cubic Zirconia Jewelry
    • How to Evaluate the Quality of Sapphire: A Buying Guide
    • How to Care for Pearls and Protect Them from Damage
    • What Does Yellow Topaz Symbolize?
    • What Are Synthetic and Created Gemstones?
    • What Is Inlay Jewelry and Should You Buy It?
    • How to Buy a Ruby: A Guide to Evaluating Quality
    • How to Detect a Fake Opal Gemstone
    • What Are Diamond Feathers and How Do They Affect Clarity?
    • What Does CTW Stand For In Diamond Jewelry?



 
  • The Magazine
    • Home
    • About Us
    • Contact Us
    • Privacy Policy and Disclosures
  • Categories
    • Jewelry Fashion
    • Shopping & Selling Tips
    • Jewelry Care
    • Gemstones
    • Metals
    • Materials
    • Jewelry Basics
  • Topics
    • Diamond Cut Quality Guide
    • Rings
    • Necklaces
    • Bracelets
    • Earrings
    • Diamonds
    • Pearls
    • Gemstones
    • Gold Jewelry
    • Silver Jewelry
    • Platinum Jewelry
  • Connect with Us
    Connect with Jewelry Notes via FacebookConnect with Jewelry Notes via Twitter

 
Copyright © 2012-2025 Jewelry Notes
All rights reserved.
27696235
Jewelry NotesLogo Header Menu
  • Jewelry Fashion
  • Shopping & Selling Tips
  • Jewelry Care
  • Gemstones
  • Metals
  • Materials
  • Jewelry Basics