As appose to all natural fancy color diamonds a natural Chameleon diamond has the ability to change its color, this unique characteristic reacts to one of two particular environmental stimuli:
Chameleon diamonds which applies to the first condition of the two mentioned above is defined as "Thermochromic" while other Chameleon diamonds that apply to the second condition are defined as "Photochromic".
Just like all natural color diamonds Chameleon diamonds are consider to be very rare and highly valuable.
Chameleon diamonds in most cases will change their Olive Green (Grayish Yellowish Green to Grayish Greenish Yellow) which consider to be their "stable color" to an "unstable color" such as: Intense Brownish or Orangy Yellow and in some case even a full Yellow. Attempts to expose a Chameleon diamond to heat revealed that there is more marked color change as appose to live it in a dark for an extensive period of time. Some Chameleon diamonds exhibits a stable Green color similar to a natural fancy Green diamonds. Unlike natural Green diamonds which derive their color due to a radiation process, the process that actually gives a Chameleon diamond its color is yet unclear, the assumption is that a hydrogen-related defect appears to be the main cause though their are some experts that don't support this theory. Trying to create the same "Chameleon" effect on any lab generated parallel simply won't work, this unique phenomenom behaivior is only observed on a natural Chameleon diamonds.
As we mentioned above Chameleon diamonds are consider to be very rare however they tend to be slightly more affordable compare to other rare colour diamond that falls in the "rarest" category such as: Red diamonds (which consider to be the rarest of them all), Pink diamonds and last but not least Blue diamonds. A Chameleon diamond value is based on several factors such as: carat weight, main body color (Green color is generally the most desire color), intensity of the color (fancy deep or fancy dark are usually most desired).