Uploaded June 2021 | Updated September 2026, 6 hours ago
For a complete write up on how to correctly identify a diamond, go to beyond4cs.com/faq/how-to-spot-a-fake-diamond
In this video, I purchased a cheap diamond tester online from eBay and used in on an existing real diamond ring that I had purchased for my wife. The diamond tester works on the principle of thermal conductivity (because diamonds are SUPERB conductors of heat due to their compact covalent structure).
The diamond tester has a light meter which lights up depending on how much heat is transmitted away from the tip after it gets into contact with the surface of the diamond.
Do take note that the diamond tester has to be used properly and angled properly to the diamond for a proper contact or you will get misleading results from the test.
If a real diamond is detected, the light bar lights up to the DIA level to indicate a real diamond and a beeping sound will be heard from the equipment.
In order to differentiate between a real vs fake diamond, this affordable tester can to correctly identify real stones vs fake gemstones with the exception of a few gemstones like moissanite. For the case of moissanite, you will need to use a diamond tester that has an electrical conductivity test or manually use a 10X loupe and check the gemstone for refractive doubling.
Higher end diamond testers like those from the Presidium brand will have such functions in place to differentiate between a real diamond and a fake diamond like moissanite.
beyond4cs.com/go/amazon-presidium
If you want a simple diamond tester and have the physical knowledge to use a 10X loupe to identify a moissanite, you can use the testers here in conjunction with that knowledge:
beyond4cs.com/go/amazon-diamond-tester
beyond4cs.com/go/ebay-diamond-tester
For a more professional level of testing to differentiate between diamonds and common gemstones, I recommend the Presidium gemstone tester:
I've also written a couple of other comprehensive guides to help you identify a diamond from other common simulants found in the marketplace. Check them out in the links below:
beyond4cs.com/faq/how-to-spot-a-fake-diamond/identify-a-moissanite
beyond4cs.com/faq/cubic-zirconia-vs-diamond
As always, the best way to ensure you are getting what you paid for when buying a diamond ring is to shop at a reliable place and buy a diamond with a GIA or AGS certificate.
For a complete write up on how to correctly identify a diamond, go to beyond4cs.com/faq/how-to-spot-a-fake-diamond
In this video, I purchased a cheap diamond tester online from eBay and used in on an existing real diamond ring that I had purchased for my wife. The diamond tester works on the principle of thermal conductivity (because diamonds are SUPERB conductors of heat due to their compact covalent structure).
The diamond tester has a light meter which lights up depending on how much heat is transmitted away from the tip after it gets into contact with the surface of the diamond.
Do take note that the diamond tester has to be used properly and angled properly to the diamond for a proper contact or you will get misleading results from the test.
If a real diamond is detected, the light bar lights up to the DIA level to indicate a real diamond and a beeping sound will be heard from the equipment.
In order to differentiate between a real vs fake diamond, this affordable tester can to correctly identify real stones vs fake gemstones with the exception of a few gemstones like moissanite. For the case of moissanite, you will need to use a diamond tester that has an electrical conductivity test or manually use a 10X loupe and check the gemstone for refractive doubling.
Higher end diamond testers like those from the Presidium brand will have such functions in place to differentiate between a real diamond and a fake diamond like moissanite.
beyond4cs.com/go/amazon-presidium
If you want a simple diamond tester and have the physical knowledge to use a 10X loupe to identify a moissanite, you can use the testers here in conjunction with that knowledge:
beyond4cs.com/go/amazon-diamond-tester
beyond4cs.com/go/ebay-diamond-tester
For a more professional level of testing to differentiate between diamonds and common gemstones, I recommend the Presidium gemstone tester:
I've also written a couple of other comprehensive guides to help you identify a diamond from other common simulants found in the marketplace. Check them out in the links below:
beyond4cs.com/faq/how-to-spot-a-fake-diamond/identify-a-moissanite
beyond4cs.com/faq/cubic-zirconia-vs-diamond
As always, the best way to ensure you are getting what you paid for when buying a diamond ring is to shop at a reliable place and buy a diamond with a GIA or AGS certificate.
