The Farnese Blue diamond, which was passed down through European royal families for about 300 years, sold Tuesday for $1.4 million more than the maximum figure experts estimated it would fetch.
Net profit for the first three months of the year stood at 439 million zlotys ($121.08 million), compared with the 453 million zlotys expected by analysts.
Chief executive Jean Sebastien-Jacques said the challenge for the industry is to ensure the benefits from the past frugal years are not lost against a backdrop of rising oil prices and increased political risk.