All About Irradiated Diamonds

You will notice that the prices of fancy color diamonds are very high. If you would like a beautiful diamond for a fraction of the price of a similar looking fancy diamond, then consider purchasing an irradiated diamond.

What Are Irradiated Treated Diamonds?

The Irradiation Process was first developed by Sir William Crookes, a gem connoisseur as well as a chemist and physicist. Sir Crookes was the first to find out what radiation does to the color of a diamond. In 1904 he conducted experiments using radium salts. When the diamonds were covered in radium salt they slowly turned a dark green, this color was visible as blotchy patches and the color did not pass the surface of the stone.

Unfortunately, the radium treatment also left the diamond strongly radioactive, to the point of not being wearable. An octahedron shaped diamond that went through this treatment was donated by Crookes to the British Museum in 1914, where it remains today, the color and radioactive level still remain the same.


We have a large selection
of irradiated diamonds

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Princess Loose Diamond 0.77 Ct Green Irradiated SI2 Clarity IGL Certified

There Are Currently Four Ways That Diamonds Are Safely Irradiated:

  1. Proton and neutron bombardment via cyclotrons :
    The cyclotron treatment is now uncommon because the treatment is direction based and due to the fact that not every diamond is cut the same, the color can be stronger in some areas than in others. For example, if the stone was cyclotroned through the back of the diamond an "umbrella" of darker color will be seen through the top of the diamond (the crown).

    If the stone was cyclotroned through the crown, a dark ring can be seen around the center rim of the diamond (also called the girdle).

    Stones treated from the side will have a deeper color on one side. Cyclotroned diamonds have a green to blue-green color that is confined to the surface of the diamond. They are later heated to 800 °C to produce a yellow or orange color. It is important to note that using this method the irradiated diamonds are only radioactive for a few hours after treatment.
    2. Round Cut Loose Diamond (1 Ct, Olive Green(Color Irradiated) ,SI1(Clarity Enhanced))style=

  2. Gamma ray bombardment via exposure to cobalt-60:
    Gamma ray treatment is also uncommon, because although it is the safest and cheapest irradiation method, successful treatment may take several months. The color produced is a blue to blue-green which penetrates the whole stone. Such diamonds are not heated.

    The treated blue color can sometimes approach that of natural Type IIb diamonds (see article Investing in Type IIa Diamonds for more info on Type IIb diamonds). As with most irradiated diamonds, most gamma ray-treated diamonds were originally yellowish in color. Diamonds that are blue before the treatment will then have a greenish tint to them.

  3. Neutron bombardment via the piles of nuclear reactors:
    Neutron bombardment is one of the two most common irradiation processes, this process produces a green to black color that penetrates the entire stone, and heating of these stones from 500–900 ° C produces an orange, yellow, brown, or pink color. Blue to blue-green stones that are not heated are separated from natural stones in the same manner as gamma ray-treated stones.
    4. Round Cut Loose Diamond (1.28 Ct, Nice Blue(Color Irradiated) ,I1(Clarity Enhanced))style=
  4. Electron bombardment via Van de Graaff generators :
    Electron bombardment is the other most common process which produces a blue, blue-green, or green color that only penetrates about 1 millimeter deep. Heating of these stones from a temperature of 500–1200 °C produces orange, yellow, brown, or pink colors.

Seven Facts About Irradiated Diamonds:

  1. If re-exposed to extreme heat such as during a repair which includes boiling, the color can change. Because of this, the treatment is not 100% guaranteed to keep its new color, however the diamond will never lose its overall coloration and become near colorless again.

  2. Irradiated diamonds are not lab created, they are natural and real diamonds.

  3. Although irradiated diamonds have color, they still have the same refractive index, because they are natural diamonds.

  4. Irradiated diamonds come in blue, green, canary yellow, or even pink as well as many other colors.

  5. Because this process is permanent, the G.I.A. will grade and certify irradiated diamonds and can also laser inscribe the diamond to notify any potential buyer that the diamond has been irradiated.

  6. All diamonds have been exposed to natural radiation over the millennia before man unearthed them, so technically all diamonds have been "irradiated".

  7. Irradiated Diamonds are treated only for the color that means that the overall clarity and or imperfections of irradiated diamonds won't change with this process. However, the imperfections will likely remain hidden than if they were they to remain colorless.


At CaratsDirect2U we offer many different colors and shapes of irradiated and other color treated diamonds, for example a wide range of round cut diamonds available in green , yellow blue and even pink or orange.

If you like fancy colored diamonds, but can't afford the price, then irradiated diamonds are a great choice. All the irradiated diamonds that we carry at CaratsDirect2U are 100% natural earth mined diamonds and conflict free.

Many of our irradiated color diamonds are clarity enhanced as well. These two processes combined, offer high-quality and desirable SI1-SI2 diamonds with a range of colors at affordable prices. We also have a large selection of irradiated jewelry such as: Invisible settings earrings, studs, pendants and engagement rings .

If you have any questions about our irradiated diamond collection please call one of our professional jewelers at 1-800-557-7095.