Chameleon Diamonds

What Is a Chameleon Diamond?

Chameleon diamonds are an extremely rare type of natural fancy-colored diamond, famous for their temporary changes in body color in response to heat and darkness. 

In a stable state, chameleon diamonds show greenish hues, with brown, green, yellow, and olive variations. But when heated to around 150 degrees, or exposed to darkness for a while, they undergo a dramatic change!

Slowly yet beautifully, the colors shift to an intense yellow or orangey hue, transforming their look and stunning admirers. This change reverts to its original state when cooled or re-exposed to light. 

The Science Behind Chameleon Color Change:

As magical as the color change looks, there’s real-world science behind it: thermochromism (color change with heat) and photochromism (color change with light). 

Chameleon diamonds contain high concentrations of hydrogen, with traces of nitrogen and nickel; these ‘defects’ create bands that allow specific wavelength ranges of light to be absorbed. When the chameleon is heated or left in the dark, those bands shift, allowing different light in.

But the exact science behind that remains a mystery to this day, which has only added to its collector appeal!

The required temperature to trigger a change is between 130°C and 230°C for a short period. 

Classic vs. Reverse Chameleon Diamonds

There are two types of chameleon diamonds, known as ‘classic’ or ‘reverse’. They both change color, but their stable and changing colors are opposite. Here’s a look at how they respond to heat and light: 

Classic Chameleons

Classic chameleons' diamonds have a stable olive-green or greenish-yellow color that shifts to brownish-yellow or yellow-orange when heated or kept in the dark. When cooled, they return to their green color. 

Classics are the most common type of chameleon diamond.

Reverse Chameleons

Reverse chameleon diamonds have a darker yellow or darker greenish-yellow color. This shifts to a lighter, more yellow or pale-green coloration when stored in darkness. They do not react to heat. Exposure to light brings them back to their original state. 

How Are Chameleon Diamonds Graded?

Diamonds are officially graded by the GIA as ‘chameleon diamonds’ when the following three criteria are met: greenish primary color, a color-change behavior, and a phosphorescence under shortwave UV light. 

They are graded like any other fancy-color diamond, using the fancy-color scale. The GIA focuses on stable color, with an additional ‘chameleon’ comment to note the change, rather than creating a separate color-grading category. This is measured under normal room temperature and lighting. Labs will also perform tests to observe if the color reliably shifts with temperature and light changes.

Without the ‘chameleon’ tag in the grading, there is no certainty that the stone is a true chameleon. So this can heavily affect the price tag or legitimacy claims.

The GIA’s nine-step fancy-color scale is as follows:

• Faint

• Very Light

• Light

• Fancy Light

• Fancy

• Fancy Intense

• Fancy Dark

• Fancy Deep

• Fancy Vivid

The Unique UV Glow

Chameleon diamonds also have a uniquely strong fluorescence and phosphorescence, which can help them be identified and classified. 

Fluorescence is a glow revealed under UV light, while phosphorescence is a glow that remains after UV exposure. This presence is completely safe to wear. 

Our 1.00 Chameleon SI1 Fancy Color Pear Diamond and 0.88 Chameleon SI2 Fancy Color Pear Diamond both exhibit a strong fluorescence. In comparison, our more olive-hued 1.02 Chameleon SI2 Fancy Color Pear Diamond presents a stronger glow.

FAQs on Chameleon Diamonds

What is a chameleon diamond?

A chameleon diamond is a diamond that changes color when heated or left in the dark. This is typically from a brown/green/yellow hue to a more intense yellow or orange hue. 

Are chameleon diamonds natural?

True chameleon diamonds are natural, having formed underground over millions of years and containing traces of nitrogen, hydrogen, and nickel. 

Artificial chameleon diamonds are caused by artificially irradiated or colored stones after mining and are not GIA-certified. 

Why do chameleon diamonds change color?

The exact science behind the color change in chameleon diamonds is still a mystery. Still, it’s believed that the presence of nitrogen, nickel, and hydrogen creates light ‘absorption bands’ that change when heated or left in the dark.

How rare are chameleon diamond rings?

Chameleon diamonds are amongst the rarest types of diamond, alongside red, blue, pink, and green diamonds. 

Is the color change permanent or temporary?

The color change of chameleon diamonds is temporary, returning to their ‘stable’ color when the temperature or light level drops. 

Can a chameleon diamond be used in an engagement ring? 

Yes! Chameleon diamond rings are an utterly unique yet great idea that will make your engagement ring a true statement.

How are chameleon diamonds graded?

Chameleon diamonds are graded when showing a greenish primary color, a color-change behavior, and a phosphorescence under shortwave UV light. 

They are also graded like other fancy-color diamonds, using the fancy-color scale and ratings for cut, clarity, and carat weight.

Does BGD offer chameleon diamonds?

Yes! We have a carefully curated selection of stunning chameleon diamonds, all GIA-certified and exhibiting a color change under the right conditions. They are available for any customized design, including chameleon diamond rings.