Natural fancy diamonds occur in nature and come in a wide range of colors – everything from red to blue to green. These naturally occurring colored diamonds are very expensive and usually out of reach for most diamond shoppers. The draw to unique colors and the need for affordable options lead to the development of color enhanced diamonds. They are a much more affordable option for those seeking fancy diamonds and are also less expensive and easier to find. There are three basic ways that color enhanced diamonds are made: irradiation, coating and HPHT.
IRRADIATION – This process for coloring manmade diamonds uses electron accelerator technology to alter the natural color found in the stone. Thanks to advances in the process and the technology used in the process, it is now possible to irradiate natural diamonds in an effective, affordable, and safe manner. Colors that can be achieved span the rainbow, and some of the most common colors achieved include yellow, green, blue, and red. Irradiated diamonds are safe to wear and pose no health risk or threat.
HPHT – This process, known as High Pressure High Temperature, is a specially developed treatment that can develop the color within diamonds, especially brown and orange ones, and increase their value. The color enhancement occurs when the stones are subjected to high heat and high pressure levels and permanently changes the color of the stone, often times darkening and intensifying the color. The most common use is to turn yellow tinted diamonds into bright yellow canary diamonds, but it can also be used to take grey and brown tinted diamonds and make them clearer and whiter.
COATING – This is an easy way to color a diamond but it is also the lowest quality method. It’s an artificial layer of coloring that is painted onto the bottom of the stone. When the light shined into the stone and is reflected back it reflects the color and shines it through the stone. So adding a red or pink coating to the bottom of a diamond will generate red tones in a clear stone or orange tints in a stone that has underlying yellow tones.
Thing to avoid with manmade colored diamonds:
Avoid temperatures over 150°F because it may affect the color of the stone, so be sure you let any jeweler know the stone is color enhanced before any work or cleaning is done.
Make sure the diamond is not exposed to any acids as they can eat away at the coloring or destroy the integrity of the stone.
Diamonds that have been artificially treated and colored they should not be re-cut or polished because any weaknesses in the stone can cause it to crack, chip, or fade.