Due to the nature of fine jewelry, the discoloration can be a common issue. For instance, gold and silver can change color because of chemical reactions. But what about diamonds, the most sought-after gemstones in the jewelry world? Can diamonds change color? Can diamonds discolour?
Diamonds can’t change color due to their nature – unless the fact that people utilize various treatment methods to discolor diamonds counts. However, there is one type of diamond that possesses the ability to change color under certain conditions.
In this article, we’ve covered everything you need to know about discoloration in diamonds, so without further ado, let’s dive in.
What Is Chameleon Diamond?
Colored diamonds are pretty unusual gemstones. However, as rare as they are, chameleon diamonds are particularly remarkable due to their qualities that no other stone possesses.
At the core of those attributes is a unique property: The ability to change color.
These gemstones adapt to their environment by temporarily changing colors. What makes these chameleon diamonds so fascinating is not just their color-changing ability but the fact that very little has been documented about them in general.
The precise definition of a chameleon diamond isn’t entirely clear, either. What is certain is that diamond experts will continue to study these peculiar stones in an effort to find more about their fascinating qualities.
For these reasons, chameleon diamonds remain a rather captivating phenomenon and a highly sought-after stone to any collector or investor.
What Do Chameleon Diamonds Look Like?
As the colors of a chameleon diamond change, many wonder what hue these stones default to in their natural state. While chameleon diamonds normally look like green diamonds, they can turn to a range of shades from the brown to yellow side of the spectrum.
So, what causes chameleon diamonds to change color? It’s a combination of heat and light that gives these diamonds their fascinating superpower.
While chameleon diamonds typically appear to be olive green or gratis-green, they can morph to an intense yellow when kept in the dark for 24 hours or more – or when they’re heated to around 200 degrees Celsius.
However, this change of color doesn’t last long. When the diamond cools down or is exposed to daylight, it will gradually switch back to its green color. Chameleon diamond usually reverts to its olive shade within 10 minutes if it changed color due to being kept in the dark.
That said, there are chameleon diamonds of another type known as reverse chameleons. These diamonds exhibit the opposite behavior: They have light yellow color that can temporarily become darker and greener when the stone is kept in the dark for a longer period of time.
Typical color combinations for chameleon diamonds are gray-yellowish, grayish-yellowish, brownish-greenish, brownish-yellowish, and green-yellow. There are o lot of other varieties, though; you can basically find any combination of yellow, brown, green, and grey.
Read Also: Do Diamonds Turn Yellow With Age?
What Causes Chameleon Diamond’s Color?
Scientists are still unable to explain these color morphing behaviors – which are, by the way, known as thermochromism and photochromism.
Still, these diamonds contain unusually high concentrations of hydrogen. They also have some traces of nitrogen and nickel in their crystal structure. This nitrogen-hydrogen combination could be responsible for the chameleon effect.
Chameleon diamond also possesses diamond fluorescence. The hues always include at least one of the following – yellow, green, brown, and gray color.
See Also: Do Diamonds Glow Under Black Light?
Chameleon Diamond’s Rarity And Prices
These color-changing diamonds aren’t just a source of interest for collectors. The only way to obtain a chameleon diamond is by buying it since they’re scarce, thus more priced than most colorless diamonds.
However, chameleon diamonds are far more affordable than the higher-priced color diamonds such as orange and pink. In addition, fancy deep or fancy dark chameleon diamonds are more sought after due to their color being stronger and the color change effect is often more pronounced.
Furthermore, the price of chameleon diamonds – just like the price of any other diamond – goes up dramatically with increased size. The phenomenon is even more noticeable with chameleon diamonds since larger gemstones of this type are extremely rare.
If you’re looking for a diamond that is “less permanent,” you may want to consider a chameleon diamond. While the base color is an olive tone, there are several hues like yellow, brown, and green.
Chameleon Diamond’s Origin
The chameleon diamond wasn’t studied until 1943 when the Gemological Institute of America stepped in. Before that, most jewelers and traders assumed these gemstones were just green diamonds. Experts at the GIA conducted experiments and tests on 29 diamonds to discover differences between regular green diamonds and chameleon diamonds.
Katerina Perez, a diamond expert, explained that a typical green diamond, exposed to extreme levels of heat, will change color permanently. In contrast, a true chameleon diamond will be able to switch back to its original color. As far as where these interesting stones come from, the GIA report states that the exact origins of chameleon diamonds remain unknown.
On the other hand, what is known is that around 40% of chameleon diamonds were purchased in India, 30% were purchased in Antwerp, and 30% were acquired in Tel Aviv.
Famous Chameleon Diamonds
There have been several notable chameleon diamonds throughout human history. For instance, the Chopard Chameleon Diamond is the biggest documented gemstone of this kind. It is a 31.32-carat oval cut diamond that boasted extraordinary clarity and color.
Another amazing example mentioned by Africa Gems is an 8.04-carat radiant cut chameleon diamond that the GIA classified as a fancy dark green chameleon diamond. This stone was set in a rose gold ring surrounded by a pave frame of smaller pink diamonds. It is estimated to be worth around $2,100,100.
Back in 2011, Katerina Perez reported that Christie’s auctioned off an 8.8-carat chameleon diamond ring that was sold for $590,000 in the end. Africa Gems also indicated a chameleon diamond set in a platinum ring that weighed over 4 carats. This jewelry piece was sold for an impressive $240,000 in a Hong Kong auction.
Chameleon Diamond Ring Settings
A chameleon diamond definitely makes for a special and unique engagement ring. Choose a setting that will match the wearer’s style and personality to optimize the beauty of this peculiar gemstone. Here are some examples of chameleon diamond ring settings:
- Ornate halo setting – A chameleon diamond deserves a sumptuous setting. Have a custom ornate halo setting planed out for your chameleon.
- Two stone setting – Pair your chameleon diamond with another gorgeous gemstone to increase the carat weight of your ring.
- Classic halo setting – Surround your chameleon diamond with tiny stones and consider a pave setting for your band.
We recommend you visit your local trusted jewelry store as they will be able to suggest the best ring settings for your chameleon diamond.
Do Diamonds Change Color With Age?
The way the diamond is formed is what determines its color. Or, to be more specific, the color of a diamond depends on what elements were present during the diamond’s formation process.
All diamonds start as carbon atoms deep below the Earth’s surface. Extreme conditions of high pressure and high temperature force these carbon atoms to form tight bonds, ultimately creating a string lattice-like network.
Over billions of years, carbon atoms continue to accumulate and create new bonds. That is how diamonds get larger – well, the simple version, anyway. If the chemical bonds are only made with carbon atoms, the diamond will look colorless. But if another element is added to the equation during the formation process, it could affect the entire structure.
Therefore the color of the diamond is also affected. Specifically, yellow diamonds are made when nitrogen atoms form bonds with carbon atoms. That is due to the fact that nitrogen absorbs blue light, which then reflects different shades of yellow color.
Even the smallest amounts of nitrogen can cause a yellowish diamond. As you see, the atomic structure of a diamond determines its color. This atomic structure is produced by numerous complex chemical reactions that happen deep below the Earth’s surface.
And since it’s impossible to change a diamond’s chemical structure naturally, it can’t change color over time, either. In other words, diamonds don’t discolor over time.
However, if your colorless diamond has developed a yellow tint, you can blame dirt, dust, and oil. Even a light layer of grime can make a white diamond appear yellow.
Other possible culprits include soap, makeup, and hairsprays. These substances can build up on your diamond over time, making it look discolored and stained. We advise you to keep your diamond away from these products. If your diamond gets dirty, be sure to properly clean it or have a professional clean it for you.
Learn More: Diamond Color Chart: Diamond Color-grading Scale
Changing A Diamonds Color
If you consider purchasing a colored diamond, you should know if its color is natural or maybe a result of a certain treatment process.
Humans have been treating diamonds to amplify their appearance for quite some time. There is nothing inherently wrong with changing the color of a diamond by the treatment process, as long as the treatment is disclosed.
The trouble arises when the treatment process isn’t disclosed because, in these cases, you may think you’re buying one thing – but in reality, you’re getting something completely different. And since diamonds are valuable and expensive, purchasing a misrepresented stone isn’t a minor issue.
Now, several processes can be utilized to alter the color of a diamond. Let’s talk about some of the more common treatment methods:
Paints And Coatings
The Italian goldsmith and sculptor boasted in the treatise of Benvenuto Cellini how he could amplify the color of yellow diamonds by using blue dye. Modern variations of this technique employ thin film coatings to produce diamonds of all colors. Low-tech variations include permanent markers and nail polish.
Irradiation And Heat
Scientists started irradiating diamonds over a century ago. Their early experiments created radioactive gemstones and color alterations confined to thin zones near the surface of the diamond.
The most common treatment methods today are neutron irradiation in a reactor and high-energy electron irradiation in a particle accelerator. Heating irradiated gemstones to above 500 degrees Celsius will alter most blue-to-green colors to brownish or yellow, or in rare cases, pink to red.
High-Pressure High-Temperature Annealing
Exposing diamonds to extremely high temperatures and high pressures can lighten the color of some brownish diamonds. In some cases, it can also be utilized to produce certain fancy colors. That is the most common treatment procedure used to created treated yellow diamond.
Low-Pressure High-Pressure Annealing
Heat treatment methods under low pressure can be used to produce black diamonds by causing graphite to form in surface-reaching fractures. The process is so common that black diamonds treated this way are much more prevalent than natural black diamonds.
Detecting the color treatments used in a diamond often requires sophisticated instrumentation and testing – the kind you can find in the best-equipped labs such as the GIA lab. Whether a diamond’s color is artificially induced or natural can almost always be determined.
On rare occasions – such as some green diamonds – testing equipment and gem identification techniques can’t positively determine the source of color, though.
If you’ve ever wondered, “Can diamonds change color? Can diamonds discolour?” we’re here to answer your crux of the matter:
Since a diamond’s chemical makeup can’t be changed naturally, it can’t discolor. However, there is a type of diamond that changes color when exposed to heat or kept in the dark. The duration of this color change is relatively short – around 10 minutes before it goes back to its original color, though.
In addition, humans have been utilizing various treatment methods to change the color of diamonds in order to enhance their appearance. High-pressure, high-heat annealing and irradiation, and heat, to name a few – but none of them really count as natural occurrences of diamonds changing color.
Read Also: What Colors Do Real Diamonds Shine?