Diamond Enhancement Guide


If you were to pull a diamond out of the ground, you would probably not be terribly impressed with its appearance. Hire a master gem-cutter and a skilled jewelry designer, however, and you would soon feel very differently about it. Diamonds and other gemstones are polished, cut, and mounted before their true beauty can be witnessed. Just as with cutting and polishing, diamond enhancement can bring out a gem's best features. When you know a bit about diamond enhancement, you can expertly select the best diamond jewelry for your personal collection.

Diamond Enhancements:

  1. HPHT treatment: HPHT stands for high pressure and high temperature. Industry professionals explain this color-enhancement process as allowing a gem-quality diamond to mature more fully by immersing it in an environment that is similar to conditions existing deep inside the earth. HPHT treatments can change the color of a diamond by altering the amount of nitrogen inside the stone or removing crystal growth. HPHT treatments are permanent. Some diamond types are identified by how much nitrogen the stones contain.

    Diamonds Types and Nitrogen:

    • Type 1a diamonds contain nitrogen and are the most abundant type of natural diamonds. The HPHT treatment changes the color of 1a diamonds to green or yellow.

    • Type 2a diamonds don't contain, or contain very little, nitrogen and are very rare, less than 2 percent of mined diamonds. The HPHT treatment changes the color in 2a diamonds to pink, blue, or colorless.

  2. Drilling: Diamonds can be drilled with lasers to provide access to inclusions, or flaws, which can then be dissolved by sulfuric acid. The diamond is not harmed by the acid, and the microscopic holes can be filled with a special kind of glass. Fractures can also be filled with glass without being drilled. Although the holes and filling can be viewed under magnification, they are not visible to the naked eye.

  3. Dyes and films: Dyes and films can be applied to colorless diamonds to give them a bright, vibrant hue. Diamonds with a natural fancy color are very rare, but color-coated diamonds offer a high level of color saturation in a more affordable piece of jewelry.

  4. Irradiation: Colored diamonds can also be produced through irradiation. Irradiation changes a diamond's crystal structure, changing colorless diamonds into orange, pink, yellow, blue, green, and black diamonds. Irradiated diamonds are safe and can give you a diamond in a rare and stunning hue.

Enhanced Diamond Shopping Tip:

  1. Make the most of your jewelry budget by understanding treatment codes and comparing enhanced diamonds with untreated natural diamonds. Consult this gemstone treatment guide when you are shopping on our site to thoroughly understand the treatments of all gemstones in our jewelry. We identify diamond treatments in each product description.

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Updated January 8, 2015