Minute master builders get gold into shape.

Tiny flakes of gold have been grown in the laboratory by microbes from gold-bearing soil. Australian researchers says that their ability to concentrate traces of gold could help explain why flakes and nuggets of gold are often found far from a seam and could lead to improved prospecting techniques. Researcher Frank Reith of the Australian National University in Canberra collected soil and gold samples from the Tomakin mine in New South Wales. In the mine itself, gold is very finely dispersed through the quartz rock, but if you pan for gold in the surrounding area, you find whole flakes. Gold crystals began to form, with the gold building up in layers, atom by atom. Understanding all the different mechanisms is critical for gold exploration, says Ernst Kohler, a gold specialist at CSIRO Exploration and Mining in Western Australia, an offshoot of the science research agency.