GENEVA >> A pear-shaped 18-carat pink diamond is set to be sold at auction today and is expected to fetch between $25 million and $35 million, Christie’s says.

The “Fortune Pink” fancy vivid pink stone, said to be the largest of its kind and shape to go on the block, headlines the auction house’s latest Geneva sale of jewelry.

Max Fawcett, head of Christie’s jewelry department in Geneva, said the stone with a strong, saturated pink color was mined in Brazil more than 15 years ago. He declined to identify its owner, but described the diamond as “a true miracle of nature.”

“We’ve had a huge amount of interest in the stone from all over the world,” Fawcett said in an interview. “It’s a truly incredible diamond.”

The auction comes six months after Christie’s sold “The Rock” — a 228-carat egg-sized white diamond billed as the largest of its kind to go up for auction — for more than $21.75 million, including fees. That was at the low end of the expected range.

The pink stone’s auction follows a showroom tour in New York, Shanghai, Singapore and Taiwan before its arrival in Geneva.

Christie’s says the first pink diamonds ever recorded were found in India’s Golconda mines in the 16th century, before others turned up over the centuries in places like Africa, Australia, Brazil and Russia.