How to Tell If a Diamond is Real: A Comprehensive Guide

Diamonds aren't just precious gemstones; they're internationally recognised symbols of status, luxury, and enduring love.

Naturally, with such a powerful allure behind these treasured stones, a common challenge arises: how to tell a real diamond from its many mimics. For centuries, many industrious opportunists have tried to make fast profits by flooding the market with clever counterfeits, some so realistic, that it takes a professional approach to spot the difference.

Now, in an era where cubic zirconia and other substitutes often masquerade as the real thing, our specialists at Pink Kimberley Diamonds have compiled some points to help investors, collectors, and sentimentalists to discern the genuine from the imitation.

The Fundamentals of Spotting Fake Diamonds

Every diamond pretender has unique characteristics, subtle hints that betray their true nature. Here’s some tips on how you can tell if a diamond is real:

Cubic Zirconia

Beware the allure of this famous diamond-lookalike. With its brilliant flash, it may be convincing – and tempting – to the untrained eye. Unlike the nuanced lustre of a diamond, cubic zirconia lacks depth, often displaying an overtly ‘flashy’ appearance. Shine a stream of light onto its surface, and you will find that rather than penetrating for a dazzling centre, it will cast distorted, rainbow-like rays across the room.


Moissanite is actually a rare type of silicon carbide in the natural world, but it can be easily created in a laboratory setting. Deceptively similar to diamonds, moissanites sometimes exude a yellow or greyish hue in specific lights. Although they are close in hardness, their refractive properties differ, with Moissanite far higher, which can be a telling sign.

Synthetic Diamonds

Once, diamonds would require thousands of years and levels of intense pressure to form into the beautiful gems we know and love.

Today, a series of revolutionary tools found in specialist laboratories can produce diamonds that are virtually identical to those found deep in the Earth's embrace. While they share many physical properties with their natural counterparts, only a trained eye can spot the slight differences.

If you're wondering how to tell if a diamond is real when up against its lab-grown counterpart, the answer is simple: speak with a professional.

White Topaz

Another beautiful stone in its own right, but not in the same league as a diamond. Magnify a white topaz, and its tale of authenticity (or lack thereof) will quickly start to unravel. They do not have the same strength as an authentic diamond, holding only eight on the Mohs hardness scale, so they are often overly scratched with wear, lacking the enduring resilience of a diamond's surface.

How to Tell if a Diamond is Real Using Methods in Your Own Home

Engaging the services of an expert jeweller to determine whether your diamond is real or a convincing fake might not be necessary – at first. There are a few tests you can easily conduct in the comfort of your home. While they aren't foolproof, they can often point you in the right direction.

Here’s what you can try:

  • Review the Quality of the Mount and Settings: If you have purchased a beautiful diamond ring or diamond pendant and are worried it’s a fake, it’s unlikely the seller will have still used precious metals for the mount and settings. Genuine diamonds, however, are typically paired with premium settings with metals like 18K gold, so an examination might just provide the clue you're looking for.
  • Let the Diamond Sink or Swim: Real diamonds have a unique relationship with water, thanks to their higher density. Should you drop them into a glass of water, they will likely sink quite quickly to the bottom. Other jewellery, however, which is far less dense, will either sink much slower or even float.
  • Heat Dissipation: A diamond’s interaction with heat, even something as fleeting as your breath, can indicate its authenticity. Real diamonds should be able to dissipate heat easily, so when you breathe onto it, the moisture should be gone in moments. Fake diamonds will take much longer.
  • Testing Transparency: The refraction play of a genuine diamond might just be its defining signature when placed over a book or piece of writing. If it’s blurry, then your diamond is likely real. If it’s clear, you might have a glass rock on your hands.

Authenticity Tests with More Specialised Appliances

For those who fancy a more technological approach, a host of specialised tools available can give you a more conclusive answer. Each offers its own method to help confirm or dispel your diamond's authenticity:

·      Diamond Density Analysis: Should you possess or have access to a precision diamond scale, you can weigh your gem and ascertain its density as a clear indicator of its genuineness. For context, a common imposter like cubic zirconia boasts a density approximately 55% greater than a genuine diamond.

·      Ultraviolet Illumination: Exposing diamonds to ultraviolet or "black light" reveals fascinating results. Some diamonds, about one in three, will emit a blue luminescence. However, this isn't a definitive test since many genuine diamonds might not exhibit this trait, and other non-diamond stones might remain inert.

·      Thermal Challenge: Diamonds, given their unparalleled structure, are resistant to swift temperature changes. If subjected to intense heat from, say, a lighter or blow torch for a brief period, followed by immediate immersion in cold water, they remain unscathed. On the other hand, many of their counterfeit counterparts would falter, often cracking under the strain.

Caution: Thermal testing carries inherent risks, and we at Pink Kimberly Diamonds advise against trying it in an unsecured environment.

How Experts Determine Diamond Authenticity

The realm of diamond verification is one of precision, expertise, and acute observation. When you find yourself at a crossroads, you can call upon experts to use a combination of sophisticated tools and trained senses:

·      Loupe Examination: Delving into the intricate world of diamonds requires a keen eye and the right tool. Using a loupe, a type of magnifying instrument, one can closely inspect a diamond's inner makeup. Armed with this tool, skilled jewellers can discern genuine diamonds from imposters by observing their unique structures.

·      Heat Dispersal Assessment: Familiar to many as the "Diamond Tester," this innovative device gauges the speed at which a gemstone disperses accumulated heat. This rate of thermal conductivity becomes a telltale sign, assisting in validating the authenticity of a diamond.

·      Precision Weight Analysis: Leveraging specialised scales designed for gemstones, one can weigh a diamond to gain insights into its density. This meticulous weighing process acts as another layer of verification, helping to confirm if the gem in question is genuine or otherwise.

Determining the Authenticity of Your Diamond Investment

Both coloured and traditional diamonds signify more than just sparkling jewels; they are assets with real, tangible value. When considering the rarity and allure of pink diamonds, in particular, their authenticity is paramount for ensuring solid investment returns. To delve deeper into understanding diamonds or for expert assistance, don't hesitate to reach out to our dedicated team.


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