Blue diamond may be a diamond, the rarity of its color in nature makes it a gemstone much more expensive than the classic white diamonds. This explains why blue diamonds regularly make headlines, each time beating price records at auctions.

It owes its color to the presence of Bore at the heart of its structure, therefore requiring particular geophysical conditions for its formation. This explains why only three mines in the world produce most of the production of natural blue diamonds :

  • Argyle Mine in Australia
  • Culligan Mine in South Africa
  • Golonconda Mine in India

raw blue diamond

Photo showing a 29.6 carat raw blue diamond from the Culligan mine owned by Petra Diamonds.


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Color shades of blue diamond

Blue diamonds can take more or less pronounced shades as shown in this color scale :

blue diamond color scale

When talking about blue diamond, it's difficult to be precise as the color panel is so wide these stones can take. Here is a summary table of the most common shades of blue :

blue diamond color shades

Blue diamonds vary in color from blue-gray to blue-green. Of course, the most pronounced blue diamonds are the most expensive (source image)

Difference with a sapphire

By consulting the previous table, we can see that the blue diamond is easily distinguished from the color of blue sapphires. In addition, sapphires with a different chemical and physical composition of diamonds make it easy to differentiate them from diamonds.

Blue diamond price beats records every time

The exceptional blue diamonds, whether of their size or their purity (IF or FL) are exchanged for sums always more crazy during the auctions:

  • In 2009 the 7-carat Diamond Star of Josephine and Flawless was auctioned for $ 9.49 million, or nearly $ 1.35 million per carat.
  • In 2011, the 35.56-carat Whittelsbach Diamond auctioned for $ 24.3 million, or $ 1.799 million per carat.
  • In 2014, the 13.22-carat Winstown Blue sold for $ 24.25 million or $ 1.83 million per carat.

    In comparison, it should be reminded that in 2007, the most expensive stone in the world at the time, a blue diamond of 6.04 carats had sold at auction for 4 million pounds sterling or close to 1.3 million dollars per carat at the then exchange rate.

    No wonder then that blue diamond has become an investment product for the world's great fortunes. As a result, these often end up in safes and are rarely mounted on jewelry.

    If all natural blue diamonds don't reach such crazy amounts, it's normal to see prices of more than $ 15,000 per carat for "normal" blue diamonds sold in jewelry or online.

    price comparative

    Blue diamond quality is evaluated according to the degree of purity of the crystal, but also according to the particular color scale of its diamonds and differs from the 4C rule used to evaluate the price of white diamonds.

    For people wishing to use blue diamonds for their jewelry without spending astronomical sums, there remains the option of treated natural diamonds of blue color.

    Treated blue diamonds

    Natural diamonds are treated by irradiation to give them a blue hue:

    • Irradiation treatment changes the diamond color (natural) superficially or totally depending on the process used. Treatment with cyclotron or by electron bombardment gives a blue color in the diamond surface while the gamma rays change the color to the diamond heart, it's however the process the least frequently used because very long (several months).

    There are other methods of treating diamonds such as HPHT (high pressure, high temperature) used for brown, yellow and pink diamonds or neutron bombardment for black and green diamonds.

    Although this method may seem artificial, blue diamonds treated are natural blue diamonds whose color has been changed subsequently. Their price is still that of diamonds, namely 1500 dollars or more per carat (the price depends also and especially their degree of purity).

    You can buy blue diamonds online, whether natural or processed on this site.

    Blue diamond of the crown

    The most famous blue diamond is certainly the blue diamond that has been part of the jewels of the French crown. Worthy of a good whodunnit, the story of this diamond was eventful.

    Crown of France

    Brought from the Indies in 1668, the raw blue diamond with an exceptional size of 115 carats was bought by Louis XIV who had it carved in an unusual form (the Paris rose) to end with a diamond of 69 carats.

    Mounted subsequently on the golden fleece by Louis XV, it will eventually be stolen after the French Revolution, bought by an Englishman which will have it re-cut in oval to blur the tracks of the concealment, resulting in an oval 45.5 carat diamond known today as Hope.

    Hope blue diamond

    If you're looking for a jewel with a blue diamond, you can use our services or look at these few examples of jewelry with affordable blue diamonds that you can find on the market.


    Free bonus : Download our complete guide on Diamond (fr).

    You'll find everything you need to buy diamonds jewelry online or in stores.

    For further :

    August 08, 2019 — Hugo Maherault

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