Mined in 2015 and weighing just over 37 carats, The Pink Raj will become one of the most expensive jewels of its type if it nets its anonymous owner such a fee.
Bids of between $20 million and $30 million would value the diamond at almost $1 million per carat.
It was displayed in the Swiss city by auction house Sotheby's at a preview event on Wednesday and goes under the hammer next week.
Source: news.sky.com