U.S. physicists have discovered a new electronic property in lodestone also known as magnetite .

Nanofabrication finds new mineral property

U.S. physicists have discovered a new electronic property in lodestone, also known as magnetite -- one of the most studied magnetic minerals on Earth.

Led by Rice University Associate Professor Doug Natelson, the physicists found by changing the voltage in their experiment, they were able to reduce magnetite's temperatures lower than minus 250 degrees Fahrenheit. That resulted in the mineral reverting from an insulator to a conductor.

"It's fascinating that we can still find surprises in a material like magnetite that has been studied for thousands of years," Natelson said. "This kind of finding is really a testament to what's possible now that we can fabricate electronic devices to study materials at the nanoscale."

The magnetic properties of lodestone were documented in China more than 2,000 years ago, and Chinese sailors were navigating with lodestone compasses as early as 900 years ago.

The new research appears in the online edition of the journal Nature Materials and will be published in the journal's February print issue