Chameleon Diamonds

What is Chameleon diamond?

Sometimes colored gemstones tend to show certain phenomenal effects when properly cut. Well informed buyers are familiar with the phenomenal effects in corundum (stars), chrysoberyl (cat's eye), alexandrite (color change), opal (play of color), sunstone (aventurescence), labradorite (labradorescence), moonstone (schiller) and aventurine quartz (aventurescence). The optical effects are due to inclusions, reflection, twinning, selective absorption or diffraction.

But there is an unusual phenomenon in diamond known in the trade as ‘chameleons’. In nature, chameleons are large lizards that are well-known for their ability to change their body color, a unique physical and physiological condition due to their mood, light and temperature, where the skin color plays an important role in adapting to the surroundings, communication among the species or rivalry fights. You may see a similar chameleon-like phenomenon in natural green diamond. The suitable natural green (grayish yellow green) diamonds react to heat and change color temporarily, becoming yellow (greenish orangish yellow), and then reverts to its stable color. When you have a large stone with the unique phenomenon, the color shift becomes easier to perceive and describe, especially if you have a comparison stone. Chameleon-like diamonds are perceived to be one of the great mysteries of the diamond world. There are various
interpretations by gem experts on the cause and effect, and most specimens are sold with lab reports. Overall it is still not known as to why these diamonds change from deep green to yellow when heated or left in darkness.

The chameleon-like diamonds are rare, and not well understood by the public, dealers and jewelers due to lack of awareness or education. One has to wonder how many chameleon-like diamonds may have slipped through a dealer’s hand due to lack of knowledge. How many jewelers have ever seen a chameleon-like diamond? Very few. Collectors who are familiar with the chameleon-like effect in diamonds often pay high premiums for large stones at international auctions. Because of its celebrity status and stunning look, imaginative designers have recognized the potential by designing chameleon-like diamonds in one-of-a-kind jewelry to create a masterpiece.

Australia’s Argyle diamond mine, famous for its fancy color diamonds also produces chameleon-like diamonds. The stones are recognized by their blue violet gray or gray yellow green color. One interpretation by the experts is that the color may be due to high hydrogen content. Experiments have been conducted in the laboratory by heating and observation to study its unusual properties. The catch-22 is heating an enhanced diamond may result in permanent modification of color. Sophisticated analytical techniques with proper skills in interpreting the test results may be required to separate chameleon-like diamonds from another type of green diamond. If in doubt always consult a reputed gem testing laboratory.