The search for the precious metal is becoming increasingly difficult. New deposits are hardly found. But there is evidence that depleted mines can fill again. Gold has never been so precious. The global demand has grown rapidly: Gold price has doubled in the past four years. Above all, Chinese and Indian jewelry manufacturers need more and more gold. Financial experts also expect more and more investors buy gold to their capital to protect against inflation. However, the replenishment falters: The search for gold is becoming increasingly difficult. New deposits are hardly found. A study now but nourishes the hope that gold reservoirs within a generation may renew (Science, vol 314, p. 288, 2006). The finiteness of the stocks is at issue. Geologists are constantly on the lookout for new deposits. But few places come into question. Gold is usually present in traces in the earth's crust and distributed combines extremely rarely with other substances. Only deep beneath volcanoes at high pressure is combined in water, under these conditions, hundreds of degrees hot, with hydrogen sulphide. The precious mixture occasionally opens the way towards the surface. As soon as the pressure or the water cools, falls the gold from the solution and collects in a so-called hydrothermal deposits on - in quartz veins, which are more than 100 kilometers long can be. Typically, it takes millions of years, until in this way constitutes a major reservoir - the scientists previously believed. But apparently can go much faster. On the island of Lihir in Papua New Guinea is an extinct volcano in the Ladolam-cut gold mine. Witches' Kitchen of the underworld More than a kilometer deep holes gave the New Zealand geologist Stuart Simmons and Kevin Brown insight into the underworld of the kitchen witches: they lowered probes into the depth and took samples of the flow solutions of gold rocks. The hot deep water transfer much more gold into the deposit as adopted, the researchers now report. The temperature difference between surface and depth they calculated the speed with which the solutions flow. Ladolam gold mine was within 55,000 years, from the deep water deposition, the researchers concluded - provided gold content and speed of the water were similar to earlier today. It was now that similar deposits formed within a few decades, says Christoph Heinrich of the ETH Zurich. Condition is merely that circulate less water than in the Ladolam mine, the gold content that is higher - and thus the precious metal could come off faster. One sixth of the gold as Ladolam reservoirs belongs to the type of ground-level, relatively cold storage facilities, which are much potassium. These deposits are now applied to find, says Hartwig Frimmel from the University of Würzburg. Some could be virtually inexhaustible.