Smart phones are ubiquitous, but the materials they're made of are "rare" -- at least rare enough to be called rare earth metals.

In recent years, economists and geologists have begun worrying that the world's supply of rare earth metals will be outpaced by demand, driving up the prices of materials vital to the production of popular electronics like the iPhone and Blackberry.

But a new study, published this week in the journal Applied Geochemistry, suggests humans could extract rare earth metals from the solid nodes of iron and manganese found strewn across much of the deep ocean floor.

Rare earth elements, or rare earth metals -- including scandium, yttrium, praseodymium and dysprosium -- are a group of 17 naturally occurring elements on the periodic table that share similar chemical properties. They're used to make a variety of household products like florescent light bulbs and color TVs, as well as larger technologies like solar panels and wind turbines.

Rare earth metals aren't as rare as their name lets on, but they are hard to come by, as they are widely dispersed amidst the Earth's crust and rarely found in large deposits the way other minerals are. Thus, they take a lot of effort to mine. For these reasons -- and others -- some worry increasing global demand for electronic technologies like smart phones could put rising pressure on the rare earth metals industry. That would be bad news for everyone but China, where 90 percent of the world's rare earth metal extraction currently takes place.

However, new research by geochemists at Jacobs University in Germany has revealed a promising technique for extracting, or leaching, rare earth metals from ferromanganese deposits on the ocean floor.

"Our pilot work on selective extraction of high-tech metals from marine ferromanganese nodules and crusts," the study's authors wrote, "showed that specific metal-binding organic ligands may have promising potential in future processing technologies of these oxide deposits."

Apple, maker of the iPhone, and other tech manufacturers are surely hopeful that these German geochemists are onto to something. If not, they could be forking over larger sums of money to Chinese mining companies in the near future.

As Thomas Graedel, professor of geology and industrial ecology at the Yale School of Forestry & Environmental Studies, recently said: "I'm not worried that we'll run out of rare earth metals, but will we have enough energy at a reasonable price to extract it?"

[Applied Geochemistry]

[Discovery News]

[State of the Planet]