General Jewellery Learning Tips & hacks

How can you tell if a diamond is real? 

How can you tell if a diamond is real? 

Wondering if a diamond is real, or looking to purchase a piece of jewellery and want to guarantee you get the real deal? Whether you’ve been gifted a glittering gem, inherited a family heirloom, or are simply curious, here’s all the ways you can ‘test’ a diamond, both at home and professionally. 

Diamond tests: 

  • The sparkle test 

Real diamonds have a unique way of reflecting light, thanks to their unmatched refractive index. When you move a real diamond under light, you should see a sparkle of white light (this is known as brilliance) mixed with flashes of colour (referred to as fire). If your gemstone is too ‘perfect’ in its sparkle, showing only bright white light without any colourful flashes, it might be a synthetic diamond. The beauty of a real diamond lies in its ability to play with light. 

  • The fog test 

Here’s a simple test you can do anywhere, anytime. Hold the diamond in front of your mouth and give it a good fog-up with your breath, as if you’re fogging up a mirror. A real diamond won’t stay fogged for more than a quick moment because diamonds are excellent at conducting heat and disperse the fog swiftly. If the stone holds the fog for too long, you might want to test it professionally. 

  • The water test 

Fill a glass with water and gently drop your gemstone into the glass. Being a high-density material, a real diamond will sink to the bottom immediately. If it floats mid-water or at the surface, it’s likely not a genuine diamond. Simple physics, but interesting results! 

Check the setting and mount 

If your diamond is set in jewellery, take a moment to inspect the setting and mount. High-quality metals like gold, platinum, or silver are typically used with real diamonds. Check for markings inside the ring’s band like “10K,” “14K,” “18K,” “585,” “750,” “900,” “950,” “PT,” “Palladium,” which are all indication of the type of metal used. A genuine diamond is unlikely to be set in a cheap metal (it’s important to note that this isn’t a definitive test, but it’s a good starting point). 

Professional tools 

For those who prefer precision, there are tools specifically designed to determine a diamond’s authenticity: 

  • Loupe: A jeweller’s loupe can reveal natural imperfections (known as inclusions) in a diamond, which are often missing in their synthetic counterparts. 
  • Electronic testers: These devices can differentiate between diamonds and other stones by measuring thermal conductivity.  

Paperwork & authenticity 

When it comes to buying a diamond, paperwork is your best friend. When purchasing a diamond, reputable jewellers will often provide a certificate of authenticity or a grading report from well-known gemological institutes. These documents are the diamond’s passport, detailing its cut, colour, clarity, and carat weight—known as the 4 Cs. Not only do these papers assure you of your diamond’s authenticity, but they also offer invaluable information on its characteristics, quality and provenance. 

When in doubt, call on the professionals 

If after all these tests, you’re still not sure about your diamond‘s authenticity, it’s time to consult a professional. A certified gemologist can perform detailed tests to give you a definitive answer. Additionally, always ensure you purchase from a retailer who provide you with authenticity guarantees, valuations, and are happy to answer any questions you may have. Any questions about your Diamond Store purchase? Chat to our friendly team here, who will be happy to answer any questions you may have.