A useful alloy of gold and silicon, called a eutectic, melts at a far lower temperature than either of its components. Until now, however, its odd behavior on the nanoscale has confounded researchers. By analyzing peculiar "nanoscale crop circles" formed from ultra-thin layers of gold on silicon, scientists at Lawrence Berkeley National Laboratory have discovered the eutectic alloy's unique properties, including its special promise for engineering and processing nanoscale materials.