The largest fancy-vivid orange diamond known to exist sold for 32.6 million Swiss francs ($36 million) at Christie’s International in Geneva.

The 14.82-carat pear-shaped stone’s price including fees was about $2.4 million per carat, according to the auction house at last night’s sale. This was a per-carat record for any colored diamond at a public sale. The gem also set a record for an orange diamond of its type, Christie’s said.

The Geneva fall auction season culminates today when Sotheby’s auctions a 59.60-carat internally flawless diamond called the “Pink Star.” It’s valued at more than $60 million, and David Bennett, who will wield the gavel, may break his 2010 record for the most expensive diamond sold in auction if it finds a buyer.

“There are buyers out there for these great rarities,” Bennett said in an interview Nov. 8. “There are moments to offer these things and there are moments when it just doesn’t feel right. This does feel like one of the right moments.”

While pink and blue diamonds regularly appear at auctions, the orange stones are much rarer.

Christie’s diamond had been with the same anonymous owner for at least 30 years, the auction house said, describing its clarity as VS1. The stone exceeded its presale estimate of as much as $20 million, or $1.3 million per carat.

“As far as orange diamonds go, it has no peer,” Alan Bronstein, a consultant in colored diamonds who knows the stone, said before last night’s sale.

Winston Diamond

The previous time an orange diamond of the same classifications appeared at auction, it weighed 5.54 carats. Known as “The Pumpkin Diamond,” it fetched $1.3 million at Sotheby’s in 1997, selling to Ronald Winston, a son of the Harry Winston founder.

The most expensive diamond at auction fetched 45.4 million francs at Sotheby’s in Geneva in 2010; the fancy, intense pink stone weighed 24.78 carats and was bought by jeweler Laurence Graff.