Does a tester detect lab diamonds?

Does a Diamond Tester Detect Lab Diamonds? The Complete Guide

With the rising popularity of lab-created diamonds in today’s jewelry market, many consumers and professionals are asking an important question: Can a traditional diamond tester detect lab-grown diamonds? This comprehensive guide explores the technology behind diamond testers, their effectiveness with lab diamonds, and what methods truly work for identification.

What Are Lab-Created Diamonds?

Lab-created diamonds, also known as synthetic or cultured diamonds, are real diamonds that have been produced in controlled laboratory environments rather than mined from the earth. These diamonds possess the same physical, chemical, and optical properties as natural diamonds because they are made of the same material: crystallized carbon.

There are two primary methods for creating lab diamonds:

High Pressure High Temperature (HPHT): This method mimics the natural conditions under which diamonds form deep within the Earth, using extreme pressure and temperature to transform carbon into diamond.
Chemical Vapor Deposition (CVD): This newer process involves placing a diamond seed in a chamber filled with carbon-rich gas and using microwaves to break down the gas, allowing carbon atoms to attach to the seed and grow a diamond layer by layer.

Unlike diamond simulants such as cubic zirconia or moissanite which merely look similar to diamonds, lab diamonds are genuine diamonds with identical hardness (10 on the Mohs scale) and refractive properties as their natural counterparts. The only difference is their origin.

How Traditional Diamond Testers Work

Standard diamond testers used by jewelers and consumers operate on one of two principles: thermal conductivity or electrical conductivity.

Thermal Conductivity Testers: These are the most common and affordable option. They work by measuring how quickly a gemstone conducts heat. Diamonds conduct heat exceptionally well compared to most diamond simulants like cubic zirconia or glass. The tester sends a small amount of heat through its metal tip into the stone and measures how quickly that heat dissipates.

Electrical Conductivity Testers: These devices measure how well a stone conducts electricity. Moissanite, a popular diamond alternative, conducts electricity while diamonds do not. These testers were developed specifically to distinguish moissanite from diamond, as both have similar thermal properties that can confuse thermal conductivity testers.

Many professional jewelers now use combination testers that check both thermal and electrical conductivity simultaneously for more accurate results. However, as we’ll explore next, even these have significant limitations when it comes to lab-grown diamonds.

Limitations of Standard Diamond Testers with Lab Diamonds

Here’s the crucial point: standard diamond testers cannot distinguish between natural and lab-created diamonds. This is because both types have identical physical and chemical properties that these testers measure.

When you use a thermal conductivity tester on a lab-grown diamond, it will register as a “diamond” because it conducts heat exactly like a natural diamond. Similarly, electrical conductivity testers will show the same results for both natural and lab diamonds because they share the same electrical properties.

This is actually a testament to the quality of modern lab-created diamonds – they are so identical to natural diamonds in their fundamental properties that basic testing equipment cannot tell them apart. This is very different from diamond simulants like cubic zirconia or moissanite, which conventional testers can easily identify as non-diamond.

For consumers or jewelers looking to verify whether a stone is a diamond (as opposed to a simulant), these testers remain useful tools. However, for those specifically trying to determine if a diamond is natural or lab-created, standard testers fall short.

Advanced Testing Methods for Lab Diamond Detection

As lab-grown diamonds have become more prevalent in the jewelry market, more sophisticated testing methods have been developed to distinguish them from natural diamonds:

Specialized Diamond Screening Devices: Several companies have created portable screening devices that can help identify potential lab-grown diamonds. These include:

De Beers’ DiamondSure and DiamondView instruments
GIA’s iD100
Presidium’s Synthetic Diamond Screener

These devices look for subtle differences in how the diamonds absorb and emit light, particularly in the ultraviolet spectrum. However, they are significantly more expensive than standard testers and typically serve as screening tools that flag suspicious stones for further testing rather than providing definitive results.

Spectroscopic Analysis: More definitive identification comes from advanced spectroscopic techniques that analyze how diamonds interact with light. These include:

Fourier Transform Infrared Spectroscopy (FTIR)
Photoluminescence Spectroscopy
Raman Spectroscopy

These methods can detect subtle differences in the crystal structure and trace elements present in natural versus lab diamonds. For example, HPHT diamonds often contain different metal inclusions than natural diamonds, while CVD diamonds may have different nitrogen aggregation patterns.

Professional Identification Methods

For definitive identification of lab-created versus natural diamonds, professional gemological laboratories employ a combination of sophisticated testing methods:

Gemological Laboratories: Organizations like the GIA (Gemological Institute of America), IGI (International Gemological Institute), and AGS (American Gem Society) have invested millions in developing techniques to identify lab-grown diamonds. They use a combination of the advanced testing methods mentioned above, along with proprietary technologies.

Growth Pattern Analysis: Natural and lab diamonds form under different conditions, resulting in different growth patterns. Using specialized imaging equipment like DiamondView, trained gemologists can observe fluorescence patterns that reveal how the crystal formed. Natural diamonds typically show octahedral growth patterns, while lab diamonds may show cubic growth (HPHT) or layered growth (CVD).

Inclusion Study: Under high magnification, the tiny inclusions in diamonds can provide clues to their origin. Natural diamonds may contain inclusions like garnet or olivine that formed in the Earth’s mantle, while lab diamonds might contain metallic inclusions from the growth chamber or distinctive crystal patterns specific to laboratory creation.

It’s worth noting that as lab diamond technology advances, identification becomes more challenging. Early lab diamonds were relatively easy to distinguish, but modern high-quality lab diamonds require increasingly sophisticated equipment and expertise to identify accurately.

Tips for Buying Authentic Diamonds

If you’re concerned about unknowingly purchasing a lab-created diamond when you want a natural one (or vice versa), here are some practical tips:

Buy from reputable sources: Established jewelry retailers with strong reputations have more to lose by misrepresenting their products.
Ask for certification: Legitimate diamonds, whether natural or lab-created, should come with certification from respected gemological laboratories like GIA, IGI, or AGS. These certificates will clearly state the diamond’s origin.
Check for disclosures: In most countries, sellers are legally required to disclose whether a diamond is natural or lab-created. Look for this information on product descriptions and receipts.
Consider the price: Lab-created diamonds typically cost 30-40% less than comparable natural diamonds. If a “natural” diamond’s price seems too good to be true, it might be.
Look for inscriptions: Many lab-created diamonds now come with microscopic laser inscriptions on their girdle indicating they are lab-grown. These can be viewed with a 10x loupe.

Remember that lab-created diamonds are real diamonds with the same beauty and durability as natural ones. The choice between them often comes down to personal preference, budget, and environmental concerns rather than quality.

Conclusion: The Truth About Diamond Testers and Lab Diamonds

To directly answer the question posed in the title: No, standard diamond testers cannot detect lab-created diamonds as different from natural diamonds. These testers can only distinguish diamonds (both natural and lab-created) from simulants like cubic zirconia or moissanite.

For consumers and jewelers who need to definitively determine a diamond’s origin, professional gemological laboratory testing remains the gold standard. Portable screening devices can provide preliminary indications, but they aren’t foolproof.

As lab diamond technology continues to evolve, the methods used to identify them must also advance. What we’re witnessing is an ongoing technological race between diamond creation and diamond identification techniques.

Whether you’re shopping for natural diamonds or interested in the more affordable and environmentally friendly lab-created alternatives, understanding these testing limitations is key to making informed purchasing decisions. And remember, a diamond’s origin doesn’t change its beauty or durability—only its story and price tag.

Visit our Jewels in Paradise shops in Aruba and Turks and Caicos to explore our collection of certified natural and lab-created diamonds, all properly identified and authenticated by leading gemological laboratories.