Enhanced or Treated Diamonds
As a diamond consumer, you’ve probably heard the term “diamond treatment” or “treated diamond,” or perhaps “enhanced diamond” and wondered what that meant.
A relatively small percentage of gem-quality diamonds are treated and they are treated for two reasons:
1 : to improve clarity or
2 : to alter color
Treatments for enhancing clarity
1: Laser drilling
laser drilling, which is a process that removes minor inclusions in a diamond to produce a clarity enhanced diamond. This process will typically create lines that resemble tiny trails, which are visible under side-view magnification. The laser may dissipate the imperfection, or chemicals may be injected into the resulting tunnel to bleach away the color. This is a more permanent process than fracture filling. However, it is highly debated whether or not this process damages the integrity of the diamonds, thereby decreasing the value of clarity enhanced diamonds in the long term
2: Fracture filling
Fracture filling is a treatment that adds a glass-like resin material to a natural diamond to close small cracks. Since the filling has the same optical illusion and refraction index as a natural diamond, it’s nearly impossible to detect the “repair” to the flaws. Fracture filling is not a permanent treatment as heat from future repairs, cleanings, and even sunlight can erode the filler or possibly darken its color, making the diamond less valuable as time goes on.
3: HPHT (high-pressure high-temperature)
HPHT is a treatment process that General Electric developed to permanently change the color of a diamond. First used to turn yellowish diamonds into “fancy” colored diamonds, this process is commonly used to turn yellow or brown diamonds into colorless diamonds to be sold at a significantly higher prices. HPHT involves putting a diamond into a pressure chamber and squeezing it at high pressure and high temperature for a short amount of time. Although some feel that this treatment should be considered a standard technique and claim that this process is just finishing the job that nature started, the Federal Trade Commission feels that it is an artificial process and requires that HPHT be disclosed. When HPHT treatment is detected in a diamond, the Gemological Institute of American (GIA) notes it on their reports as “HPHT Annealed” or “Artificially Irradiated” and insists that such diamonds be laser-inscribed with the same designation. A diamond that has been enhanced by GE will be inscribed with the symbol “GE POL”.
Color Enhancing or Changing
Treatments can enhance colors. To enhance or change colored diamonds, several techniques can be used.
1 : HPHT: This is the process of combining high pressure with high temperature. This technique may make a diamond more colorless, or it may create a pink, brown, yellow, or blue diamond. The resulting color will rely a lot on the original state of the diamond.
2 : Heat Treatment: When black diamonds are desired, they can be produced by taking a lower quality diamond and exposing it to very high temperatures for a period of time.
3 : Irradiation: Black, green, and blue diamonds can be created by exposing the diamond to radiation.
4 : Irradiation and Heat Treatment Combined: First, the diamond is treated through radiation, and then it is exposed to high temperatures. Diamonds which are purple, pink, blue, yellow, and brown can be created in this manner.
5 : Coating: This practice isn't as commonly used today, but it involves the coating of the stone to improve its appearance.