Diamonds or Duplicates? Your DIY Guide to Verifying Diamond Authenticity

January 20th, 2024

A cushion-cut diamond sits in a pair of tweezers.

In a world where diamonds are often imitated or misrepresented, ensuring the authenticity of your precious gemstone is paramount. While professional gemological assessments are the gold standard, there are methods you can employ from the comfort of your home to test the legitimacy of your diamonds. In this guide, our experts have carefully compiled five techniques that will help you assess whether your diamond is genuine or not. Whether you're a passionate diamond enthusiast or simply want to verify the value of a cherished heirloom, these DIY methods will equip you with the knowledge to make informed decisions about your precious gems.

A group of diamonds with different cuts on a turquoise surface.

Fire Test

It's important to note that this method should be approached with caution, as it may damage or even ruin a fake diamond. To conduct the fire test, you'll need a lighter and a glass of ice water. Using the lighter, carefully heat the diamond for about 40 seconds. After heating, immediately drop the diamond into the glass of ice water. The drastic temperature change is designed to test the diamond's thermal conductivity. If the diamond is genuine, it will remain unaffected, as real diamonds are highly resistant to thermal shock. However, fake diamonds, which are often made of materials like cubic zirconia or moissanite, may crack or shatter due to the extreme temperature difference, revealing their true nature.

A fake diamond in blue lighting appears scratched.

Scratch Test

The scratch test is a traditional method for assessing the authenticity of a diamond, although it should also be approached with caution. Take a loose diamond and attempt to scratch it on a clean, unblemished mirror or glass surface. If the mirror receives a scratch while the diamond remains unscathed, it is an indication that the diamond is likely genuine. Real diamonds are one of the hardest natural substances on Earth and can only be scratched by another diamond. However, it's important to note that this method may not be foolproof, as there are some synthetic materials that can also scratch glass. Therefore, it's recommended to use this test in conjunction with other diamond authentication methods.

A group of diamonds reflect light while sitting on a gray surface.

UV Light Test

Utilizing a UV light source to test the authenticity of a diamond is a common method employed by gemologists and jewelry experts alike. When exposed to UV light, most diamonds will emit a distinct blue glow, which can serve as an indicator of their authenticity. While this test is valuable, it's important to note that not all diamonds exhibit this blue fluorescence. The presence or absence of fluorescence alone is not a definitive indicator of a diamond's authenticity. Therefore, the UV light test is best used as part of a comprehensive assessment that combines multiple factors and tests to determine the true nature of a diamond.

A diamond necklace and matching studs in a jewelry box.

Newspaper Test

Another simple, at-home method that can offer some insight into the authenticity of a diamond is the newspaper test. To administer this test, place the diamond face-down on a newspaper page. If you can clearly read the print through the diamond, even if it appears slightly distorted or blurry, it may indicate that the diamond is likely fake. This method relies on the fact that diamonds have a high refractive index, which should make the text illegible when viewed through a genuine diamond. However, it's essential to remember that this test is not foolproof, as some genuine diamonds may still allow text to be read to some extent, depending on their cut and quality.

A group of round-cut diamonds sit on a blue reflective surface.

Seek a Professional Appraisal

When it comes to ensuring the authenticity of your precious diamond, there's no substitute for the expertise of a trusted jeweler. At Lenox Jewelers, our team of experienced professionals specializes in the careful evaluation of diamonds. We offer comprehensive appraisal services that go beyond simple authentication, providing you with valuable documentation and peace of mind. Our experts utilize a range of advanced tools and techniques to assess your diamond's authenticity and provide a thorough evaluation of its quality. Whether you're looking to confirm the legitimacy of a treasured heirloom or simply want to know more about your diamond's characteristics, our appraisal services are designed to meet your needs with precision and accuracy. 

A round-cut diamond sits in a crowd of glass shards.

Trust Your Diamonds to Lenox Jewelers

For reliable diamond authentication, look no further than Lenox Jewelers, your dependable Fairfield jewelry store. Our dedicated team of experts is committed to not only assessing your cherished diamonds but also guiding you through the journey of maintaining their beauty and value. Whether you need a professional appraisal, a cleaning and maintenance service, or intricate jewelry repair, we are here to provide the utmost care and expertise. Your diamonds are not just gemstones; they hold sentimental and emotional value, and we understand the significance they carry in your life. Request an appointment for a personalized consultation today, and let us demonstrate our commitment to preserving the beauty and integrity of your diamond jewelry, ensuring it continues to shine brightly for generations to come.