By their very nature, rare gems have always enjoyed a status as the apex of exclusivity and luxury, available only to the very wealthy who can afford the premium prices that their scarcity demands. Despite the economic slump, the jewellery market remains active. Colourless diamonds are making record prices at auctions and the value of important gemstones has increased. According to leading auction house Christie's, prices are still on average higher than they were a decade ago. Last year, the auction house sold jewellery worth more than US$93.6 million, including Kashmir sapphires and Burmese rubies sold for more than US$1.2 million each. Jonathan Abram, of Hong Kong jeweller Ronald Abram, said the financial crisis has had a minimal effect on the rare stones market but that more commercial items had been affected by as much as 50 per cent. 'Bear in mind that over the past six years prices have increased significantly,' Mr Abram said. 'We feel that the effect of the financial crisis simply served as a correction to the market.' Mr Abram said that the price per carat today was higher than two years ago, but it was lower than eight months ago. He said large stones were always in demand, particularly in an economic environment when those disillusioned with financial markets looked to diamonds as an alternative. 'Diamonds are an excellent store of value and are extremely portable,' he said. 'Today, we find that yellow diamonds are in demand because yellow diamonds of fine quality in larger sizes are much more difficult to come by than white diamonds. Yellow diamonds have also retained their value more so than the whites during the crisis.' Important gemstones are classified as rare gems of value and exceptional quality, with rubies, sapphires, emeralds and colourless and coloured diamonds considered the most outstanding. Top jewellery houses that can afford to bid for raw gems as they come onto the market, such as Graff, De Beers and Harry Winston, are among the few to have handled - literally - some of the world's most exceptional stones. Graff's Joeanna Li said the company's founder, Laurence Graff, the so-called King of Diamonds, had set an unsurpassed standard of excellence and innovation in the industry. 'It has already been said that more important gem quality diamonds have passed through his hands than any other dealer,' Ms Li said. 'These stones are extremely rare by their size, colour and origin, and most of them are also rich in history.' Recent acquisitions by the company include the Letseng Legacy, a rough stone of 493 carats mined from the Letseng Diamond Mine in Lesotho in Southern Africa. The stone was the 18th largest ever discovered. Graff used the latest technology to cut and polish the stone, which was made into three pieces: a pair of pearl-shaped earrings weighing 132.59 carats, a round diamond ring with diamond shank and pear-shaped diamond shoulders with a weight of 43.63 carats, and a 55.61-carat multicut diamond brooch. Ms Li said that each diamond was unique, which required many hours of work. 'We are dealing with the very best that Mother Nature gave us,' she said. 'Our skilful jewellers are selecting and assembling the best matching stones to create pieces that enhance the beauty of the individual stones. Very often, the final piece is like a statement on its own.' Harry Winston offers 'only rare, exceptional and utterly timeless' jewels. 'From the legendary Hope Diamond to the Lesotho Diamond to our current Incredibles collection of rare collectors' gems, the history of the house of Harry Winston includes some of the most famous jewels in the world,' said Sandrine de Laage, vice-president of design. The Incredibles collection includes vivid Paraiba tourmaline, padparadscha sapphires and mandarin garnets. According to Ronald Abram, the founder of Ronald Abram jewellers, the Holy Grail for diamond collectors are fancy vivid pink and blue diamonds, which are by far the rarest of any coloured diamond. It says that for every one fancy coloured diamond, there are 10,000 white diamonds. Coloured diamonds are judged by their saturation of colour on a grading of faint to fancy deep, with fancy intense or fancy vivid, offering the highest saturation. Ronald Abram's creations include a fancy vivid pink diamond ring of three plus carats and a fancy vivid blue diamond ring, also of three plus carats. The stones are set in micropav? rings in order to show their beauty. Jonathan Abram said: 'We have sought out these highly prized fancy vivid pink and blue diamonds, which are exceptionally rare and seldom seen at such high colour saturation.' As a natural phenomenon, rare gems are by nature in short supply. Jonathan Abram said that for the most part the rarest gems were already mined out. Sapphire mines in Kashmir have been exhausted, Columbian emeralds were no longer being produced and Burmese rubies were extremely scarce, he said. 'It is true that coloured diamonds are rare but they are still being mined today; it is only a matter of time and money and you will be able to find a coloured diamond,' he said. 'This is not the case for rubies, emeralds or sapphires. These items are irreplaceable and truly exceptional.' While the rarest gems are often categorised as rubies, sapphires and emeralds, other gemstones are equally hard to come by. According to Tayma Fine Jewellery, many of the rarest gemstones, such as Paraiba tourmaline, will be mined out within five years, 'so they really are nature's own limited editions', said Tayma Page Allies of Tayma Fine Jewellery. She said the gem was highly sought for its 'fantastic neon blue colour and luminescence', and was already more expensive than diamonds. She said a Brazilian mine in Paraiba state offered up a few small gems 'but with an amazing neon turquoise colour'. She said rough Paraiba had been mined in Mozambique and prices increased monthly due to demand from top jewellery houses 'whose clients want something different, beautiful and rare'. 'Paraiba tourmalines are hypnotic and addictive,' she said. Pricing stones, such as Paraiba tourmalines, is extremely difficult. While diamonds are regulated by world price guide Rappaport, there is no price guide for coloured gemstones. Pricing is done on a case-by-case basis taking into consideration the colour, cut, size and location of country - Brazilian gems are more expensive than African ones, for example. Ms Allies said the value of Paraiba ranged between HK$300,000 and HK$1 million. According to Tayma, Tanzanites discovered in the 1960s, Namibian Mandarin Spessartite garnet discovered in the 1990s and Tsavorite garnet from Russia are extremely rare. Fine-quality Rubellite tourmalines are also increasingly difficult to source, as are pink and padparadscha sapphires and violet Tanzanite, which is only found in one location in Tanzania. The increasing prices of such stones reflected their rarity, the jeweller said.