(IDEX Online) - Two landmark pink diamonds are to be sold within a week.Christie's Geneva today announced details of the forthcoming sale of the 18.18-ct Fortune Pink, the largest pear-shaped fancy vivid pink diamond ever to be auctioned.It will be offered for sale on 8 November with an estimate of CHF25m to CHF35m (just over $25m to $35m).Then, separately, on 15 November, Angola's state-owned diamond trading company will sell the 170.2-carat Lulo Rose, believed to be the largest pink diamond found in the last 300 years, at a rough tender.Earlier this month (7 October) a private collector from Florida, USA, paid $57.7m at Sotheby's Hong Kong for the 11.5-carat Williamson Pink Star, setting a new world record for the price per carat ($5,178,124) at auction for any diamond or gemstone.Christie's Geneva, announcing the sale of the Fortune Pink at its Magnificent Jewels auction, said: "With its auspicious weight of 18.18 carats (which translates to definite prosperity) this exceptional pink diamond of phenomenal colour will certainly bring good fortune to its new owner."Pic of Fortune Pink, courtesy Christie's