An enhanced diamond is a natural diamond that is treated or modified to alter, remove, or minimize the appearance of imperfections. These enhancements can improve a diamond’s clarity and color – two of the four factors that determine the value of a diamond.
A diamond may undergo one of several different treatments in the course of its refinement. When purchasing a diamond, it’s important to know which treatments it has undergone and how each treatment affects the diamond.
The three types of enhancements a diamond may undergo are clarity treatments, fracture filling, and color enhancement.
To start, the clarity of a diamond refers to the number of inclusions and surface blemishes a diamond has, while the clarity grade a diamond receives describes its internal purity. The fewer imperfections, the higher the value the stone is ascribed. While most diamonds contain some flaws, it is the size, number, position, nature, and color of these flaws that determine the clarity grading a diamond receives. Common inclusions that can appear are black carbon spots, fractures, air bubbles, and mineral deposits.
Two treatments can enhance a diamond’s clarity and minimize or erase the appearance of these inclusions. In laser drilling, an infrared laser bores a microscopic hole from the surface of the diamond to the inclusion (usually a black carbon spot). Once the laser drills a channel, the diamond is then soaked in a solution of sulfuric acid, which dissolves the black carbon crystal. The tiny drill holes from the laser can only be seen under a microscope and do not distract from the diamond’s brilliance or beauty.
In fracture filling (the next step in the process and second type of clarity enhancement), the channel is filled along with other small cracks inside the diamond. Usually, specialty glass solutions that match the diamond’s refractive index are used to fill these fractures.
The second of the four C’s – color – refers to the presence or absence of color in a diamond. Colorless allow the most light to pass through, meaning they will sparkle the most. While colorless diamonds are rare, there are several processes that can alter a diamond’s color into a more desirable hue.
Irradiation with high-energy subatomic particles can safely alter the color of a diamond. During this process, the diamond is bombarded with neutrons and electrons, which will change the color of a diamond to various shades of blue, green, pink, orange, and yellow.
Another method of changing a diamond’s color is to use a surface coating. Different coatings can either whiten a yellowish diamond, or add color to a white diamond.
Finally, high pressure high temperature treatment (HPHT) can significantly modify and remove color from either rough or cut diamonds and permanently alter a brown diamond to a white one. This treatment utilizes the same geophysical forces that created the diamond. By recreating these similar factors in a controlled setting, this treatment is able to permanently manipulate a diamond’s color.
When selecting a diamond it is important to be knowledgeable about these different treatments, as each can significantly affect price, quality, and rarity. These enhancing processes can take a flawed, yellowish natural diamond, and turn it into one with no inclusions and perfect color. It all depends on what the purchaser wants. Either way, it is important to remember that while these diamonds are enhanced, they are still natural diamonds, and therefore, valuable in their own right.