The Blue Moon Diamond

A wonderful new addition to the great gemstones of the world is the Blue Moon diamond, a 12.03 carat Fancy Vivid Blue, Internally Flawless diamond.

The rough diamond was discovered in January 2014, at the Cullinan mine in South Africa, the same mine where the Star of Africa was discovered one hundred years earlier. The stone weighed 29.6 carats in its rough state. Luxury Jeweller Cora International purchased it for almost twenty-six million dollars, a world record price per carat for a rough diamond. After a few months study, and careful planning, a 12 carat cushion modified brilliant diamond was produced. The stone was sent to the GIA laboratory for grading, where it received the wonderful clarity grade of Internally Flawless, and the colour grade of Fancy Vivid Blue. The colour is caused by trace amounts of Boron in the gem, and happened when the stone was formed, 100 miles under the surface of the earth, a billion years ago.

The stone has an unusual feature in that it exhibits phosphorescence, a reaction to ultraviolet where the stone glows for a short period of time after the light source is removed. (Another famous gem which shares this effect is the Hope Diamond). However it shows no obvious fluorescence under UV light.

The diamond was on display in the Natural History Museum of Los Angeles until January 2015. It is presumably to be sold in the near future, and will hopefully remain viewable to the public afterwards.

The owners, Cora International, have a wonderful video on their website,, showing the cutting process of the diamond, along with some quite stunning close-ups! (Video present as of 18/2/15)