A pink diamond weighing in at almost 19 carats is set to go on tour before being auctioned in Geneva and could fetch a record price of between $30 million (£23 million) and $50 million, Christie’s auction house announced on Tuesday.

The rectangular cut Pink Legacy is rated “vivid”, the highest rating for a diamond’s colour, and weighs 18.96 carats, making it the largest fancy vivid pink diamond Christie’s has ever offered for auction.

It was once part of the Oppenheimer collection, Christie’s said, referring to the family who built De Beers into the world’s biggest diamond trader.

Its exceptional provenance will no doubt propel it into a class of its own as one of the world’s greatest diamonds,” said Rahul Kadakia, international head of jewellery at Christie’s.

Only four vivid pink diamonds of over 10 carats have ever been offered for sale at auction, with a record price per carat set last November when Christie’s Hong Kong sold “The Pink Promise”, an oval-shaped diamond of just under 15 carats, for $32,480,500.

The Pink Legacy will be shown in Hong Kong, London and New York before being auctioned by Christie’s Geneva on Nov. 13.