Environment & Science

The Blue Moon Diamond comes to Los Angeles County's Natural History Museum

The Blue Moon Diamond, an internally flawless 12-carat diamond, will be on display at the Natural History Museum of Los Angeles County through Jan. 6, 2015.
The Blue Moon Diamond, an internally flawless 12-carat diamond, will be on display at the Natural History Museum of Los Angeles County through Jan. 6, 2015.
Eloïse Gaillou
The Blue Moon Diamond, an internally flawless 12-carat diamond, will be on display at the Natural History Museum of Los Angeles County through Jan. 6, 2015.
The Blue Moon Diamond phosphoresces orange-red for about 20 seconds, while most blue diamonds show a short bluish phosphorescence.
Tino Hammid/Cora International LLC
The Blue Moon Diamond, an internally flawless 12-carat diamond, will be on display at the Natural History Museum of Los Angeles County through Jan. 6, 2015.
The Blue Moon Diamond was sold earlier in the year for $25.6 million to Cora International.
Tino Hammid/Cora International LLC


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Although the main attraction at Los Angeles County's Natural History Museum may not typically be a gem, this could change with the unveiling of the Blue Moon Diamond on Saturday.

The Blue Moon Diamond, an internally flawless 12-carat fancy vivid blue diamond cut from a 29.6-carat rough, will be on display through Jan. 6, 2015, according to a press release from the museum.

Eloïse Gaillou, associate curator at the museum, told KPCC the diamond is not only exceptional in size and color, but also in its discovery.

“It’s been over 100 years that there was no big blue diamond discovered,” Gaillou said, “and now suddenly we have this exceptional diamond coming out of the [Cullinan] mine in South Africa.”

Gaillou explained that diamonds are formed in the mantle of the earth, where liquid carbon eventually cools and hardens to form a diamond. She said that the rarity of blue diamonds lies behind the disturbance the element boron can have on the carbon structure of a diamond.

“Boron is not really supposed to be inside the earth’s mantle,” Gaillou said. “Most of the boron we find on the earth is on the surface.”

Gaillou said boron gets into the mantle of the earth either because it was there since the formation of the Earth and never managed to go above the surface or because of plate tectonics. She said the Blue Moon Diamond is most likely a result of the latter.

The Blue Moon Diamond was sold earlier in the year for $25.6 million to Cora International, which loaned the diamond to the museum, according to Gaillou.

The diamond will be displayed on its own pedestal at the Gem Vault in the museum, Gaillou said.