Cutting the Blue Moon diamond

Suzette Gomes, CEO of Cora International, with the Blue Moon diamond on exhibit at the Museum of Natural History of Los Angeles County. Photo by E. Chamorro for NHMLA.

Did you check the Blue Moon diamond on display at Natural History Museum of Los Angeles County? You will see that we added the resin models of the different steps of the cutting process. Thanks to information provided by Cora International and the master cutter, here is the description our volunteer Brittany gathered. It is interesting to see the process of having an extremely valuable rough blue diamond and making a decision on how to cut it to yield the best color, clarity and shape. Enjoy!

The added resin models on display at the Natural History Museum of Los Angeles County. Photo by E. Gaillou for NHMLA.

The Blue Moon Diamond is one of the rarest diamonds in the world. Therefore the cutting process is a rather meticulous procedure. The rough diamond must first be placed into the hands of a master cutter. Most master cutters have been working in the trade for decades. The master cutter will examine the natural growth features of the rough diamond. From there, many models of the stone will be made. Creating models at every stage is a very important and significant part of the cutting process. These models give a blueprint to follow in creating this beautiful and extremely rare gem. Each model will be marked to determine the best shape and size of the stone. Once the model is marked, the cutter will begin to form facets into the model on the cutting wheel. 

Zoom in on the models. The numbers you read represent the carat weight of some steps of the cutting process.Photo by E. Gaillou for NHMLA.

The first two models created, weighing 22.79 cts, help determine the shape that would give the highest yield in weight and to also achieve an “Internally Flawless” diamond grade. One model was created in to a “square cushion” shape and the other in to a “long cushion” shape.

The Blue Moon diamond at 22.79 carats. © Cora International.

Now at 19.30cts, it was determined that the “longer cushion” shape would give a slightly higher yield in weight and more assurance to achieve the “Internally Flawless” grade.

The Blue Moon diamond on the cutting wheel. © Cora International.

The Blue Moon diamond at 19.30 carats. © Cora International.

The Blue Moon diamond at 19.30 carats. © Cora International.

At 16.31 cts the crown facets were preliminary blocked in and prepared for the shaping process. The results are examined and the model begins to take shape. Another replica model was created with pavilion facets at 15.29cts. This model determined how the deep indented naturals would be removed while retaining optimal weight and achieving an “Internally Flawless” clarity.

Once 14.21cts were reached, it was known that the gem had now achieved the “Internally Flawless” clarity grade. After achieving the final result on the model, the rough diamond was then able to be faceted on the wheel and polished into one of the rarest and most exquisite diamonds in the world.

The Blue Moon diamond at 14.21 carats. One already can see the beauty of the stone! © Cora International.

The making of the Blue Moon Diamond

In a short video produced by Cora International, here is the making of the Blue Moon Diamond, from the 29.6-carat rough to the 12-carat Fancy Vivid Blue, Internally Flawless gem. The Blue Moon Diamond is on display at the Natural History Museum of Los Angeles County until January 6, 2015. Come and see it: it is included in the regular entrance to the museum!

A SPECIAL DIAMOND EXHIBIT AT NHM Los Angeles, running through January 6, 2015

The reunion of exceptional diamonds

Beginning September 13, 2014 and until January 6, 2015, we will have a special reunion of diamonds at NHM: The Blue Moon Diamond will meet the Butterfly of Peace diamond collection. The collection of 240 natural fancy-colored diamonds that make the spectacular Aurora Butterfly of Peace is already worldwide renown and well traveled: it had been on special exhibits at the Smithsonian Institution and at the Houston Museum of Science, just to cite only a few of the prestigious places it has seen. The Butterfly of Peace will have a new companion beginning September 13: The Blue Moon Diamond, which was recently discovered in South Africa. Now faceted from the 29.6-carat rough, the 12-ct stone will also be displayed in the Gem Vault of the Natural History Museum of Los Angeles County.

The renown Aurora Butterfly of Peace: 240 natural fancy-colored diamonds. All known colors of diamonds are represented in this unique and exceptional collection totaling 167 carats of beauty. The collection is not only a delight for the public but also for the scientists to study. The variety of colors makes it the best tool to analyze the color in diamonds. On loan from Aurora Gems. Photo by Robert Weldon. Copyright: GIA.

The 12-carat Fancy Vivid Blue Moon Diamond. Recently discovered in South Africa, this diamond shows the most exquisite of the blue colors. Such as the Butterfly of Peace diamond collection, the Hope diamond, or the Wittelsbach-Graff, it was studied at the Smithsonian Institution before coming on exhibit to our museum. On loan from Cora International. Photo by Tino Hammid. Copyright: Cora International.

The Aurora Butterfly of Peace on exhibit at NHM

Add 240 fancy-colored diamonds, the rarest of all the gems. Arrange it carefully in a butterfly shape that took the owner (Aurora Gems) over 10 years to put together. Obtain a delightful art-piece that will be a joy for the public and the connoisseur to look at!

The Aurora Butterfly of Peace on exhibit at NHM. Photo and copyright: K. Stone.

The Aurora Butterfly of Peace as seen on its display case. Photo and copyright: E. Gaillou for NHM.

A different look at the Butterfly of Peace! Photo and copyright: E. Gaillou for NHM.

I would like to quote my colleague George Harlow from the American Museum of Natural History (AMNH): when the Butterfly of Peace was on exhibit at the AMNH, he mentioned that their colored diamond exhibits have “the highest slobber factor of anything in the gem house” with “nose prints and handprints” commonly found on the glass. We would concur with that! Good thing that our display cases are cleaned every morning...

The Blue Moon Diamond: from rough to cut

The 29.6-carat rough stone was unearthed at the Cullinan Mine in South Africa by Petra Diamonds in January 2014. In February, Cora International bought it and began the cutting process in April 2014. The cut stone was finished at the end of June. The photos below show you a few steps of the cutting process from the rough to the cut stone. Before cutting the blue stone, models of it were made and cut. No rough stone is perfect to begin with, and inclusions and impurities have to be avoided during the cutting process so that the cut stone doesn't have any inclusion in it. The design of the stone was so well done that the stone has been graded "Internally Flawless" by GIA.

The rough 29.6-carat Blue Moon Diamond on the cutting wheel. Copyright: Cora International.

The first "window" is open in the diamond. It is from this first facet that the other ones will be built from. Copyright: Cora International.

More facets are polished. Isn't it scary to see such a valuable diamond in such position?! Copyright: Cora International.

Some of the front facets are polished, while the back of the Blue Moon is still rough. Copyright: Cora International.

The Blue Moon diamond on the cutting wheel. Copyright: Cora International.

Almost there! But still a few more facets to be cut on the back of the stone. Copyright: Cora International.

On this shot, we already can see the finished shape of the stone. It begins to look like a little brother of the Hope diamond!

The Blue Moon Diamond will be on display in the Gem Vault of the NHM from September 13, 2014 until January 6, 2015, next to the Butterfly of Peace diamond collection. It will most likely be the ONLY public appearance of this diamond, so rush in! Especially that you can see this special reunion of exceptional diamonds with a regular NHM admission.

On view at:

Natural History Museum of Los Angeles County

900, Exposition Bvd

Los Angeles, CA 90007

(213)-763-3466