If you are wondering whether lab diamonds pass a diamond tester, the short answer is yes. In most cases, lab grown diamonds will test exactly like natural diamonds because they have the same chemical, physical, and thermal properties.
This is one of the most important facts buyers should understand before purchasing a lab created diamond. A standard diamond tester is designed to identify whether a stone is a real diamond, not whether it was formed naturally or grown in a laboratory.
That means certified lab grown diamonds usually pass traditional diamond testing tools without any issue. However, there are important details worth knowing if you want to understand how testing works, how jewellers identify lab diamonds, and what this means when buying loose lab diamonds.
Learn more about >> Do Lab Diamonds Sparkle Like Natural Diamonds?
Why Lab Diamonds Pass Diamond Testers
Lab diamonds pass a diamond tester because they are real diamonds.
Both natural and lab grown diamonds are made of pure carbon arranged in the same crystal structure. They also share nearly identical hardness, brilliance, and thermal conductivity.
Most handheld diamond testers work by measuring thermal conductivity. Diamonds transfer heat differently than other gemstones like cubic zirconia or moissanite. Since lab grown diamonds conduct heat the same way as mined diamonds, the tester reads them as genuine diamonds.
This is why a standard diamond tester cannot reliably distinguish between:
- Natural diamonds
- Lab grown diamonds
It can only separate diamonds from diamond simulants.
Read another question >> Can a Diamond Tester Detect a Lab Grown Diamond?
What Does a Diamond Tester Actually Detect?
A diamond tester is not checking where a diamond came from. It is checking whether the stone has diamond-like properties.
The most common testers measure:
Thermal Conductivity
Traditional testers send heat through the stone to see how quickly it transfers energy.
Real diamonds, including lab grown diamonds, transfer heat extremely well.
Electrical Conductivity
Some advanced testers also measure electrical conductivity to help separate moissanite from diamond.
Moissanite can sometimes confuse older thermal testers because it also conducts heat efficiently. Modern dual testers are better at identifying the difference.
Still, lab diamonds normally test positive as diamonds because they are genuine diamonds.
Learn more about >> Do Lab Diamonds Pass a Diamond Tester?
Can a Diamond Tester Tell if a Diamond Is Lab Grown?
No, not a standard diamond tester.
A regular jeweller’s tester cannot usually determine whether a diamond is natural or lab grown. Both stones react almost identically during basic testing.
To identify a lab grown diamond accurately, professionals often use specialized equipment designed for diamond origin detection.
These advanced tools may analyze:
- Growth patterns
- Fluorescence
- Crystal strain
- Microscopic inclusions
- Spectroscopic characteristics
This type of equipment is typically found in professional gemological laboratories or high end jewellery stores.
Read another question >> Can a Diamond Tester Detect a Lab Grown Diamond?
Do All Lab Diamonds Pass Diamond Testers?
Most certified lab grown diamonds will pass standard diamond testers without issue.
However, a few factors can affect results:
Poor Quality Testers
Cheap or outdated testers may give inconsistent readings.
Low battery power, improper calibration, or weak probes can also create false results.
Very Small Diamonds
Tiny melee diamonds can sometimes be harder to test accurately because there is less surface area.
Moissanite Confusion
Older testers may incorrectly identify moissanite as diamond. This is why modern multi testing devices are preferred.
Still, genuine lab diamonds are expected to pass properly functioning diamond testers.
Are Lab Diamonds Considered Real Diamonds?
Yes. Lab diamonds are real diamonds.
This is one of the biggest misconceptions buyers face when comparing natural and lab grown stones.
Lab diamonds are not fake diamonds, imitation stones, or cubic zirconia. They are chemically and optically real diamonds created in controlled laboratory environments instead of underground over billions of years.
Because of this, they:
- Pass diamond testers
- Receive diamond certifications
- Have the same sparkle and durability
- Rank 10 on the Mohs hardness scale
If you want a deeper explanation of authenticity and composition, reading about whether Diamonds Are Forever style myths apply to modern stones is less useful than understanding actual gemology and certification standards used today.
How Jewellers Identify Lab Diamonds
Professional jewellers usually cannot identify a lab diamond just by looking at it.
Even experienced experts often need advanced equipment to determine origin.
Many certified lab diamonds include microscopic laser inscriptions on the girdle. These inscriptions may reference the grading laboratory and identify the diamond as laboratory grown.
Common grading laboratories include:
- IGI
- GIA
- GCAL
When shopping for loose lab diamonds, certification is important because it confirms:
- Diamond authenticity
- Lab origin
- Cut quality
- Clarity
- Colour grade
- Carat weight
A certified diamond provides much more confidence than relying on a simple tester alone.
Lab Diamonds vs Diamond Simulants
Buyers often confuse lab diamonds with simulants, but they are very different products.
Lab Grown Diamonds
Lab diamonds are real diamonds with the same composition as mined diamonds.
They pass diamond testers because they are genuine diamonds.
Cubic Zirconia
Cubic zirconia is a synthetic stone that only imitates the appearance of diamond.
It does not have the same thermal properties, so most testers identify it as non diamond.
Moissanite
Moissanite is another diamond alternative that looks visually similar but has a different composition.
Some older testers may confuse moissanite with diamond, though newer testers are much more accurate.
Understanding this distinction helps buyers avoid misinformation when comparing prices and quality.
Should You Worry About Diamond Testing When Buying Lab Diamonds?
In most cases, no.
If you are purchasing certified lab grown diamonds from a reputable source, passing a diamond tester is not usually a concern because real lab diamonds are expected to pass.
Instead, buyers should focus more on:
- Certification
- Cut quality
- Value for money
- Transparency
- Return policies
- Diamond grading consistency
A high quality lab diamond with strong certification offers the same visual beauty and durability as a mined diamond, often at a significantly lower price.
Why Many Buyers Choose Loose Lab Diamonds
Loose lab diamonds have become increasingly popular because they give buyers more flexibility and control.
Choosing a loose stone allows you to:
- Compare multiple diamonds side by side
- Prioritize cut quality
- Select the exact shape and carat size you want
- Customize your final jewellery setting
- Compare value more effectively
Many buyers researching whether lab diamonds pass a diamond tester are also trying to confirm authenticity before making a purchase decision. Understanding that lab diamonds are genuine diamonds helps remove much of that uncertainty.
If you are comparing options, it is also useful to explore related questions about whether lab grown diamonds are the same as natural diamonds and whether a jeweller can tell the difference between lab and natural diamonds. These topics help create a clearer picture of what you are actually buying.
What Matters More Than Passing a Diamond Tester
Passing a diamond tester only confirms that a stone behaves like a diamond.
It does not tell you whether the diamond is:
- Well cut
- Properly certified
- Good value
- Ethically sourced
- Visually appealing
This is why experienced buyers focus on overall diamond quality rather than relying on a handheld tester alone.
For lab diamonds specifically, the most important factors are usually:
- Excellent cut grade
- Reliable certification
- Strong visual performance
- Competitive pricing
- Transparent sourcing
These factors influence beauty and value far more than a simple tester result.
Final Thoughts
Lab diamonds do pass a diamond tester because they are real diamonds with the same core properties as natural stones. Standard testers measure diamond characteristics like thermal conductivity, not geological origin.
For buyers, this is actually reassuring. It confirms that lab grown diamonds are genuine diamonds rather than imitations.
When shopping for loose lab diamonds, the smartest approach is to focus on certification, cut quality, and overall value instead of relying solely on basic testing devices. A properly certified lab diamond offers the same beauty, durability, and authenticity many buyers want, often with greater affordability and flexibility.