Colored diamonds in and of themselves are an unusual find. As rare as they are, however, chameleon diamonds are particularly awe-inspiring because of certain qualities that no other stones possess. At the core of those characteristics is a unique power: the ability to change color.
These diamonds, true to their name, actually adapt to their environment and temporarily switch colors, switch hues. What makes these stones so fascinating is not only their color-changing capability, but also the fact that very little has been written about them. In fact, the precise definition of chameleon diamonds is still not entirely clear. What is certain, though, is that experts will continue to study these gems in an effort to learn more about their incredible qualities.
For these reasons, chameleon diamonds remain an intriguing phenomenon and a highly sought-after addition to any connoisseurs or investor’s collection.
Here’s what is currently known about these remarkable gemstones.
What do they look like?
As chameleon diamonds’ colors change, many wonder what hue they default to in their natural state. While they normally appear to be green diamonds, they can morph to a range of shades from the brown side of the spectrum to yellow.
So what causes their hue to switch? It’s a combination of light and heat that gives these stones their superpower. Chopard explained that while typically these diamonds will look olive green or greyish-green, they can shift to an intense yellow or orangy-yellow when kept in the dark for a full 24 hours or more, or when they are heated to about 392 degrees Fahrenheit. This change doesn’t usually last long, though.
When the stones cool down or are exposed to daylight, they will gradually go back to their green hue. Katerina Perez, a gemologist, noted on her blog that a diamond typically revert to its olive shade in 10 minutes if it changed hues due to being stored in the dark. She also revealed that not all chameleons go from a darker hue to a light one – some shift colors in the reverse, from yellow to green.
What causes their color?
Researchers are still unable to thoroughly explain these color-changing behaviors, which are known as thermochromism (a switch in response to heat) and a photochromism (a switch in response to light). Still, these diamonds all contain unusually high concentrations of hydrogen, as well as traces of nickel and nitrogen, in their crystal structure. This nitrogen-hydrogen complex could be responsible for the chameleon effect. Some experts believe that chameleon diamonds have luminescent and phosphorescent properties.
When did they emerge?
It wasn’t until 1943 that the first chameleon diamond was studied at the Gemological Institute of America. Before that, most traders and jewelers assumed these stones were simply green diamonds. Specialists at the GIA conducted a series of experiments and tests on 29 diamonds to determine the differences between typical green stones and chameleons. Katerina Perez explained that an ordinary green diamond that is exposed to extreme heat will permanently change colors, whereas a true chameleon will be able to return to its original hue.
Famous Chameleon Diamonds
As far as where chameleon diamonds come from, the GIA report stated that the exact origins remain unknown. What is known is that about 40 percent of these stones were purchased in India, 30 percent were bought in Antwerp and 30 percent were acquired in Tel Aviv.
There have been several notable chameleon diamonds thus far. The Chopard Chameleon Diamond is the largest documented stone of this kind is a 31.32-carat oval-cut chameleon diamond that boasted exceptional clarity and color is an especially striking example.
Another amazing stone cited by Africa Gems is an 8.04-carat radiant-cut diamond that the GIA classified as a fancy dark grey green chameleon. This diamond was set in a rose gold ring surrounded by a pave frame of small pink diamonds, and is estimated to be worth about $2,100,000.
Katerina Perez reported that back in 2011, Christie’s auctioned off an 8.8-carat chameleon diamond ring in Hong Kong, and it ultimately sold for $590,000.
Africa Gems also pointed to a chameleon diamond, weighing over 4 carats, that is set in a platinum ring. This piece fetched an impressive $240,000 in a Hong Kong auction.