Automatic Gem Cutter: Fire Up the Ruby Bot

Getting a perfect diamond or ruby from a raw stone has always been more art than science. Each gem must be meticulously cut and polished by hand. The problem: It can take up to four hours and leave nearly 70 percent of the nugget in a pile of dust on the floor.

So researchers at Germany's Fraunhofer Institute for Industrial Mathematics built the world's first automatic gem cutter. The machine shines bands of light across an uncut stone to chart its surface. Then, using proprietary software, it calculates optimal dimensions for the completed jewel. Finally, a cutter grinds along 17 axes. The process takes about an hour and leaves an average of 15 percent more of the original rock intact.

Depending on the stones being cut, the $1.2 million rig can pay for itself in just one week, says Karl-Heinz Küfer, who designed its software. Plus, there's a lot less ruby dust to sweep up.