When Emma Edwards Green designed Idaho’s state seal in 1890, she gave emphasis to the mining industry by depicting a man with a shovel and pick along the right side of her painting.

“As mining was the chief industry, and the mining man the largest financial factor of the state at that time, I made the figure of the man the most prominent in the design,” she later wrote.

Today, the world’s hunger for minerals has again put the spotlight on the state’s mining industry.

Industry experts say Lemhi County, along the state line with Montana, could hold the key to unlocking the answer to the shortage of the world’s rare earth minerals. Those such as neodymium, lanthanum and cerium are used in everything from cellphones to military weapons to green technology.

It’s likely that only California, Alaska and Wyoming top the Gem State in the amount of rare minerals within their borders, said Virginia Gillerman, an economic geologist for the Idaho Geological Survey.

Those resources continue to become more valuable. China, which produces more than 90 percent of the world’s rare earth minerals, has warned that it will curb its exports.

An Arkansas mining company, U.S. Rare Earths, is searching for the buried treasure within the rock near the Idaho-Montana state line.

U.S. Rare Earths did not respond to repeated requests for comment.

“We know from geology that there are rare earths out there ... (but) no one has ever really started looking out there (before) because it costs a heck of a lot of money,” said Russ Bjorklund, Salmon-Challis National Forest minerals program manager.

RARE EARTHS IN IDAHO

The nation’s hunt for uranium began in 1945 after the end of World War II.

That exploration turned up an interesting discovery in Lemhi Pass: thorium. It’s considered a safer, more abundant alternative to uranium in nuclear fuel, Gillerman said.

The need for thorium was minimal and extraction was stopped. Prospectors didn’t realize that spidered through the rock, alongside the thorium, were rare earth minerals that decades later would be some of the world’s most coveted resources.

“Early studies by the U.S. Geological Survey concluded that this district had the largest thorium resource in the nation and also hosted an equal amount of rare earths,” according to a January 2011 Idaho Geological Survey journal article.

Throughout Idaho are large deposits of neodymium (used in magnets), lanthanum (studio lighting and projector lights) and cerium (televisions), Gillerman said.

Mining those minerals remains difficult and expensive, meaning it’s not likely to happen soon.

“Like any mining project, a company has to prove there is enough in the ground to make it economically worthwhile to extract — and that they can extract it efficiently,” Gillerman said.

EXPLORING IN LEMHI

“A couple of years ago, prices (for rare earths) spiked up and everybody got excited, talking about shortages,“ Gillerman said. Mining in Idaho “depends on whether China sells them to us.”

The minerals are accessible, but the price has to be right. The rare earth elements are mixed together in the rock near the Idaho-Montana line. To separate them requires an expensive chemical process, Gillerman said.

Until that point is reached, U.S. Rare Earths continues exploring. It has submitted three plans to the Salmon-Challis National Forest, two of which have been approved. In one area, the company has started drilling core samples, used to pinpoint mineral veins, Bjorklund said.

Neither Gillerman nor Bjorklund knows whether the company found what it was looking for.

The next step in the company’s quest is to apply to mine, Bjorklund said.

“We’re still far out from any actual production,” Gillerman said. “We don’t even have a good estimate of the volumes of minerals yet.”