Sotheby's is to present at its Geneva sale of Magnificent Jewels on the November 16, a very rare and very large (24.78-carats) pink diamond with an estimate of 27 million to 38 million Swiss Francs. According to the house it is one of the most important gemstones ever to come up for sale. Graded a Fancy Intense Pink by the Gemological Institute of America (GIA), the stone is a very attractive vibrant pink, a bright hue unlike lesser grades of pinks that can  look watery or washed out. Once the property of Harry Winston, it was purchased some 60 years ago by a private collector and once again is on the market. Exceptional in many ways, not only is the colour mesmerising,but this stone has also lucked out on the size front. And what's more, the GIA believe that if re-polished the stone could be internally flawless. Bingo! Keep an eye out for the auction results as records may be broken.