Do Lab-Grown Diamonds Pass A Diamond Tester?

Lab grown diamonds are gaining recognition for their quality, beauty, and value—but one question often arises during the buying process: Can a lab grown diamond pass a diamond tester? The short answer is yes—but the full explanation reveals a deeper, more technical story.

At Simone & Son, we believe in educating our clients with accuracy, care, and transparency. As a third-generation jeweler in Huntington Beach, CA, our goal is to guide you with expertise rooted in both tradition and modern gemology.

A Bit of History: Where Did Diamond Testers Come From?

Here’s something most people don’t know—diamond testers have only been around since the late 20th century. Before that, jewelers had to rely on loupe magnification, refractive index tests, and years of experience.

Thermal testers were a breakthrough in the 1980s. But the game changed again when moissanite and lab grown diamonds entered the scene in the '90s and 2000s—forcing new tech to emerge.

Today, lab testing and gem certification are the gold standard.

What Does a Diamond Tester Actually Test?

A diamond tester is a small handheld device that helps distinguish a diamond from diamond simulants like cubic zirconia. The most common testers fall into two categories:

Thermal Conductivity Testers

These measure how quickly heat moves through a stone. Diamonds—both natural and lab grown—have extremely high thermal conductivity.

Key Point: Lab grown diamonds conduct heat in the same way as natural ones.

Electrical Conductivity Testers (Dual Testers)

These test both thermal and electrical conductivity. Moissanite, a diamond lookalike, has similar thermal properties to diamonds but differs electrically.

Dual testers can distinguish diamonds from moissanite—making them more accurate for modern use.

So, Do Lab Grown Diamonds Pass the Test?

Yes.

Lab grown diamonds pass both thermal and dual-mode diamond testers because they are chemically and physically identical to natural diamonds.

They share:

• Carbon atom structure

• Thermal conductivity

• Refractive index

• Hardness (10 on the Mohs scale)

From a scientific standpoint, a lab grown diamond is a real diamond. That’s why reputable jewelers—like Simone & Son—use gemological certifications, not just testers, to ensure full transparency.

How Reliable Are Diamond Testers?

While diamond testers are useful tools, their accuracy can vary depending on the context.

Thermal Testers

• Accurate for distinguishing diamonds from cubic zirconia or glass

• Struggle to tell moissanite from diamond

Dual Testers

• Detect lab grown vs moissanite with high precision

• Accurate up to 98–99%

FACT: The GIA and AGS recommend dual testers when verifying stones in the lab or in high-end retail environments.

Unknown but Important: Limitations of Diamond Testers

Diamond testers were originally designed in the 1980s, when the main concern was distinguishing diamonds from glass or cubic zirconia. The rise of moissanite and lab grown diamonds has created new challenges.

Important Limitations

• Cannot detect origin (lab vs natural)

• Cannot provide grading (clarity, color, cut)

• Can give false readings if the stone is dirty, loose, or in a setting

That’s why certification is critical. Simone & Son provides GIA or IGI certification for all major stones, backed by our in-house gemologists and 35+ years of industry experience.

Are There Better Alternatives to Diamond Testers?

Yes. Jewelers often rely on a combination of:

• Magnification (loupe/microscope): to examine inclusions or growth patterns

• UV light tests: to detect phosphorescence

• Advanced lab analysis (Raman spectroscopy, FTIR): used by labs like GIA

These methods, along with certifications, give the clearest view of a diamond’s quality and origin.

Related Questions About Lab Grown Diamonds and Testing

Can You Tell If a Diamond Is Lab Grown Without Tools?

No. Even trained gemologists cannot tell by sight alone. Only specific instruments or reports can confirm the origin.

Do Lab Grown Diamonds Glow Under UV?

Sometimes. Lab diamonds may fluoresce under UV, but so do many natural diamonds. It’s not a definitive test.

What Is the Best Way to Confirm a Diamond’s Authenticity?

A gem certification report from a trusted source (GIA, IGI, GCAL) is the gold standard. At Simone & Son, every significant diamond includes one.

Why Choose Simone & Son for Your Diamond Purchase?

At Simone & Son, our reputation is built on expertise, integrity, and craftsmanship. Here’s what sets us apart:

Certified GIA gemologists on staff

• All work done in-house, from design to setting

• Detailed jewelry appraisals for insurance and valuation

• Lifetime cleaning, resizing, and rhodium services

Whether you're purchasing a lab grown diamond engagement ring or a custom heirloom, we provide total transparency—because trust is the most valuable gem.

Visit Simone & Son in Huntington Beach, CA

Looking to explore lab grown diamonds or test an existing stone? We invite you to visit our showroom and speak with our gemology experts.

Simone & Son

10124 Adams Ave, Huntington Beach, CA 92646

(714) 964-4012

✉ info@simoneandson.com

Book your consultation today and experience the difference of a family jeweler who values precision, care, and your story.