A 59.6 carat pink diamond could become the most expensive precious stone of its class on Apr. 4 at an auction organized by Sotheby’s Hong Kong, the company said Wednesday.

The “Pink Star” diamond was presented in Hong Kong on Wednesday, six days before it was to go on sale, and the final bid could exceed $60 million, according to expectations of the auction house.

It was the biggest pink diamond in existence and was even larger in the past – 132.5 carat at the time of its extraction in 1999 – before being cut and polished, said the Geological Institute of America.

“The extraordinary size of this diamond, paired with its richness of color, surpasses any known pink diamond recorded in history,” said worldwide Chairman of Sotheby’s Jewellery Division, David Bennett.

The “Pink Star” was auctioned in 2013 by Sotheby’s Geneva and was sold at $83 million – even more than the current price expected – but the jeweler who offered the bid did not pay for it and hence the stone was returned to Sotheby’s.

“We are in the place and moment to sell this piece,” said Bennett, remarking that “in four years lots of new billionaires are in the market.”

Until now, the record for the most expensive diamond ever auctioned has been held by the 14.6 carat blue diamond, which was sold by Christie’s last year for $57.5 million.