The price eclipsed the previous record of $46.2m established three years ago by Sotheby's Geneva for the Graff Pink - a 24.78 carat fancy intense pink diamond.
The Pink Star was cut from a 132.5 carat rough diamond mined by De Beers in Africa in 1999. It is the largest internally flawless fancy vivid pink diamond that the Gemological Institute of America (GIA) has ever graded and they awarded it their highest colour and clarity grades.
It was also found to be part of the rare subgroup comprising less than 2% of all gem diamonds known as Type IIa. Stones in this group are chemically the purest of all diamond crystals and often have extraordinary optical transparency.
Unveiled as the Steinmetz Pink in Monaco in 2003, the stone was first sold privately in 2007 and subsequently renamed The Pink Star.
A vibrant market for coloured diamonds saw it appear at auction for the first time with an estimate of $60m. Four bidders competed before it was bought by the New York diamond cutter Isaac Wolf who has renamed it The Pink Dream.
The day before at Christie's equivalent sale on November 12, The Orange, a pear-shaped, fancy vivid orange, VS1 diamond of 14.82 carats sold at $35.5m (£23.5m), setting a record per carat for coloured diamonds.