What Is A Chameleon Diamond?

You know about coloured diamonds. But did you know about chameleon diamonds? If your bride-to-be wants a truly unique engagement ring (and you have unlimited funds), it could be just the ticket.

As you might have guessed, a chameleon diamond has a special talent that sets it apart from other diamonds; much like the lizard, it can change colours. Its ‘true’ hue is somewhere between grey and murky yellow-green. But when heated up to 150 degrees celsius (302 degrees fahrenheit) or exposed to light after a prolonged period in darkness, its hue temporarily transforms into an intense orange-yellow or dark orange-green colour. The effect can last for up to an hour, with the colour change slowly fading into a subtle glow before the stone returns to its original colour.

Sounds pretty cool, right? Here’s the effect in action:

This magical gemstone first came to the fore in 1866, thanks to a Parisian diamond merchant named Georges Halphen. Although extremely rare, specimens showed up at various intervals over the following decades and by 1943 the name ‘chameleon diamond’ was coined. Apart from that, little historical details are known.  

Despite its magical ability to change their hue, chameleon diamonds are still relatively unknown. In fact, according to the GIA a customer back in the 1970s purchased what he thought was a light yellow green diamond. When he later opened the ring box to take a look, a dark green diamond sat inside… so he took it back to the store for a refund!

Why exactly does this colour change occur? That’s the real mystery about these diamonds – nobody knows! Because they’re so rare and so few specimens have been found, researchers have yet to get a real opportunity to study them. Since both heat and light cause the colour change, it’s likely that more than one factor is at play. Some experts attribute it to higher than usual levels of hydrogen, nickel and nitrogen.

While it’s virtually impossible to find chameleon diamonds, there have been a few famous examples over the years. The Chopard Chameleon Diamond is the largest known gem of its kind, weighing in at 31.32 carats. In 2011 Christie’s featured an 8.8 carat chameleon diamond in ring in an auction in Hong Kong, which sold for $590,000.

So start saving, or start buying lottery tickets and hope for the best!