Geneva: The ultra-rare 11.16-carat pear-shaped Bulgari Laguna Blu – certified as the highest grade blue diamond ever by the GIA – was auctioned for just over $25m at Sotheby’s Geneva on Tuesday.

It became the most valuable gem ever to be sold by Bulgari, after a four-minute bidding war between three parties on the phone and one in the showroom.

It was the highest price paid in the Magnificent Jewels and Noble Jewels event that brought in a total of $85m. More than half the  133 lots sold above their high estimates.

“The sale of the Laguna Blu tops the remarkable performance of our Magnificent Jewels and Noble Jewels sale that saw exceptional colored gemstones, in particular emeralds and yellow diamonds, punch through their high estimates, in such a spectacular fashion,” said Olivier Wagner, Sotheby’s Geneva head of jewelry.

The Laguna Blu was the third-largest pear-shaped fancy vivid blue diamond ever to come to auction.

A European collector bought it from Bulgari in the 1970s and had it set in a ring. It had remained in their collection ever since.