Fact Sheet on Enhanced Diamonds


When you're shopping for fine diamond jewelry, you may see some diamonds labeled as clarity enhanced. An enhanced diamond is a natural diamond that has been treated to alter or remove imperfections. These flaws affect transparency, color, and sparkle, but the enhancements increase beauty. A diamond labeled as clarity enhanced has undergone one or more of the following treatments: laser drilling, fracture filling, or HPHT treatment.

Clarity and Color Enhancements:

  1. Laser-drilled clarity enhancement: The laser-drilling process makes discolorations within a diamond less visible. A jeweler uses a laser to drill a channel from the surface down to the flawed area, often a dark carbon crystal. The heat from the laser fixes many discolorations, but sometimes the jeweler must also fill the laser channel with a solution that lightens dark patches. After the desired result is achieved, the diamond is rinsed and polished. This process is often followed by fracture filling to repair the channel.

  2. Fracture-filled clarity enhancement: The fracture-filling process makes small cracks inside a diamond less visible. The cracks (fractures), called feathers, have jagged, feathery edges. During the treatment, a jeweler drills into the diamond and fills the fracture with a glass-like substance, making the imperfection invisible to human vision. The filler and the diamond have similar refractive properties, so the enhanced area will have a sparkle that nearly matches the rest of the diamond.

  3. HPHT color enhancement: Diamonds often have impurities which affect the color. The high-pressure, high-temperature treatment, also called the HPHT treatment, improves the color of natural light-brown diamonds. A specialized cubic press recreates the conditions inside the earth that formed diamonds over millions of years. After the treatment, diamonds may have the colorless appearance of the most desirable gems or a vibrant fancy color, such as blue or yellow. Type 1a gems, the most abundant diamonds, contain nitrogen and become green or yellow with HPHT treatment. Type 2a gems, which are rare, contain few impurities and become pink, blue, or colorless. The HPHT process is permanent, so the new diamond color will never fade.

Enhanced Diamonds vs. Natural Diamonds:

  1. Clarity enhanced diamonds retain the same chemical composition as natural diamonds.

  2. Only a diamond that has never undergone any treatment to improve its color or clarity can be called a natural diamond.

  3. At Overstock™, any jewelry that contains clarity-enhanced diamonds will be identified in the product description.

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Updated January 8, 2015