Discover all about Fancy Blue Diamonds

One of the rarest of the fancy colors, blue diamonds of high color grades and weights over 1 carat are extremely expensive but also breathtakingly beautiful. In the realm of fancy blue diamonds, it is not unusual to find a .25 carat blue diamond with a five-figure price tag. Especially over the past few years, blue diamonds have been breaking and setting tremendously high price-per-carat records in prestigious auction houses such as Christie’s and Sotheby’s.

Interestingly, blue diamonds conduct electricity due to the boron contained within their atomic structure.

Cause of Color

Blue diamonds are Type IIb diamonds, which means that they contain trace amounts of the element boron in their atomic structure. Rarely is a specimen found that can be classified simply as blue; most blue diamonds include secondary colors such as grey and violet, caused by hydrogen impurities, or green, caused by nitrogen impurities.


Fancy blue diamonds are mined mostly in India and Africa, and sometimes are found in Brazil and Australia as well. The world’s only prominent blue diamond producing mine is the Premier Diamond Mine near Pretoria, South Africa.

Famous Blue Diamonds

The Hope Diamond is considered not only the most famous blue diamond in the world, but the most famous of all diamonds. It is renowned for its deep indigo blue color, its large, 67.125-carat size, and the fabled bad luck it has bestowed on its owners. Named for one owner, Henry Thomas Hope, it is said to have been cursed by the Hindu God from whose statue it was originally stolen. It was later sold to King Louis XIV of France, who had it cut into a 67.125 carat stone and gave it to Marie Antoinette.

It currently sits in its own display room, adjacent to the main exhibit of the National Gem Collection, in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals in the Smithsonian Museum of Natural History in Washington, D.C.

Due to its fame, some mistakenly think that the Hope Diamond is also the largest fancy blue in the world. However the fancy light blue Idol's Eye, weighing in at 70.21 carats, is the largest blue diamond ever to be sold publicly.

The Wittelsbach-Graff Diamond, a 35.5 carat wonder, is one of the largest historic blue diamonds ever fashioned, and the largest Flawless or internally Flawless natural Fancy Deep Blue diamond ever graded by the Gemological Institute of America. The diamond first became legendary in the 17th century, when Philip IV of Spain gave it to his daughter, the Infanta Margarita Teresa, upon her engagement to Emperor Leopold I of Austria. The diamond ended up with the House of Wittelsbach, a ruling Bavarian family, in 1722. It belonged to the Bavarian House of Wittelsbach until it was sold at an auction in London in 1931. In December 2008, the diamond was sold at Christie’s London to jeweler Lawrence Graff for just over $24.3 million, a record price for any diamond. In January 2010, the diamond was controversially recut to enhance the stone's color and clarity, losing over 4.45 carats in the process and renamed the Wittelsbach-Graff.

Because the Wittelsbach-Graff Diamond and the Hope Diamond have similar color and other similar characteristics, there has been widespread speculation that they were cut from the same crystal. The Summer 2010 issue of Gems & Gemology squashed those claims when it published observations that demonstrated that the two do not share a common source stone.

Other famous blue diamonds include:

  • The Blue Heart Diamond, a beautiful deep blue 30.82 carat diamond.
  • The Heart of Eternity, a 27.64 carat blue heart shape with the highest color grade of fancy vivid blue;
  • The Transvaal Blue, a 25 carat pear cut blue diamond.
  • Investing in Blue Diamonds

Fancy blue diamonds are one of the world’s rarest commodities, and they have been selling for record-breaking prices over the past few years. Natural blue diamonds are in high demand, but in increasingly short supply. They are ranked 4thon the list of rarest diamond colors. Anyone would agree that in a world where nothing is for certain, a fancy blue diamond is an obvious choice for someone looking for a serious investment in a commodity with lasting value.

The prices of fancy blue diamonds have been rising steadily over the past few decades and show no sign of slowing. If anything, they continue to gain desirability to diamond collectors and enthusiasts alike as they become scarcer.

Allow our experts to assist with you with all of your diamond investment questions and concerns.

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