Tellurium: Rock For a Hard Place?
By Jeff Duewel, Grants Pass Daily Courier
 

For more than two decades, Michael Cope has probed old newspapers, pored through historical documents and excavated rocks in Josephine County.

“I’ve been on this treasure hunt,” says the 60-year-old Cope, a former Teamster and freight handler who has devoted his life to geology and small-scale gold mining since about 1990.

“It’s such an opportunity.”

Cope’s treasure hunt leads to tellurium, an element considered the rarest of earth, even though it’s not technically classified as rare earth. A key ingredient in some types of solar panels, the world’s total refined supply is somewhere around 120 tons.

The U.S. Department of Energy in 2010 identified tellurium as a rare metal that could be in high demand or short supply between 2011 and 2025.

Tellurium is precious to the world and to Cope, who’s been pursuing it ever since he stumbled across the story of a “mystery metal” in Josephine County creating a stir in the 1920s. Cope believes it was tellurium. More on that later.

As the founder of American Mining Research in Grants Pass, his eyes light up when talking about the potential in minerals lying under the trees.

Undeterred that not a single hard rock mine, other than aggregate gravel for construction material, operates anywhere near Josephine County, he believes it’s possible the county’s mineral wealth far exceeds the county’s timber wealth.

“We’re the richest brokest county in the state. It’s crazy. It’s an injustice,” Cope says.

Some geologists are intrigued with tellurium and its presence in Josephine County. You can find a chunk of tellurium-bearing rock in the basement of the Josephine County Courthouse, where samples from the former state geology office are displayed.

“(Josephine County) is probably a good place to look for more,” says Oregon State University geology Prof. John Dilles, who has brought students to Grants Pass to do sampling with Cope. “There are a lot of occurrences in Josephine County. It turns out the rocks down there, lot of black shales, things that form in the ocean basin, tend to be higher in tellurium than other types of rocks.

“I don’t think there are giant deposits of tellurium waiting to be extracted, but undoubtedly if people spend the money and look for it, they’ll find some tellurium deposits that are rich enough to mine. One thing that would hurt them a lot is the cost of permitting and environmental things. It takes a long time, particularly in Josephine County, with fish and wildlife issues.”

The Benton Mine, the largest employer in the county prior to World War II, generated $3.1 million in revenue in 2007, with gold ore processed in Merlin.

But it was shut down by the state over environmental issues. Cope has expressed interest in reviving that mine, and others here, to extract tellurium. He said sampling at the Benton showed significant levels of tellurium.

“Tellurium is out there. We just have to get it out of the ground,” he said.

Rare Earth

Tellurium is so rare it makes up only one part per billion by weight of the earth’s crust. The world total refined supply is somewhere around 120 tons, according to the United States Geological Survey.

First discovered in 1782 by the Austro-Hungarian minerologist Franz Muller von Reichenstein, tellurium is a metalloid and semiconductor primarily used as an alloy with copper and stainless steel to make these metals more workable.

Tellurium is sometimes found free in nature. More commonly, it is found combined with metals, such as in the minerals calaverite (aka gold telluride) and sylvanite (aka silver-gold telluride). Commercially, tellurium is obtained as a byproduct of electrolytic copper refining.

In pure form, specimens have come from Fata Bali in Transylvania, Romania, and Kalgoorlie, Australia. It has also been found in Japan. In the U.S. it has been found in several places, mostly notably in Colorado.

Similar to selenium and sulphur, it is used as a coloring agent in ceramics, in vulcanizing rubber and in blasting caps. It can be added at very low levels to lead to decrease the corrosive action of sulfuric acid in batteries and to improve the lead’s strength and hardness.

Tellurium is also used in the electronics industry to form photosensitive semiconductors. A near-infrared detector on the Hubble Telescope is partly composed of tellurium. Cadmium telluride is used as a thin film in solar panels to convert sunlight into electricity.

Demand for tellurium is rising in tandem with the growth of solar power, which increased 418 percent from 2010 to 2014, according to the U.S. Energy Information Administration. That’s because solar panels using cadmium-tellurium cells are gradually encroaching on the predominant silicon-based cells, because they work better in low light and at a wider temperature range.

“We believe it’s THE technology,” said Steve Krum, director of Global Communications for First Solar, which manufactures solar panels outside Toledo, Ohio.

Krum wouldn’t say where First Solar gets its tellurium. Or where it might be in the United States.

So where is the tellurium? It’s almost never found in pure form, but as tellurides, or salts or combinations with other metals.

Tom Wylie, former state geologist based in Grants Pass, at the urging of Cope, two years ago applied for a $85,000 grant from the United States Geological Survey to study tellurium. He noted the prospects for solar energy.

“If their process (cadmium-tellurium) became the preferred process for solar, yeah, there could be a lot of demand,” Wylie said.

That grant did not come through, because the USGS program sponsoring it ended.

“Chances are production (of tellurium) would be along with a gold mine, the same way bulk production is associated with copper production in other parts of the world,” Wylie added. “It would take a bigger deposit than what we’ve run into yet to make a paying mine.”

Cope wouldn’t mind finding that bigger deposit. He wants to build an assay lab for testing ores, and a research lab in Grants Pass.

“We could have a tellurium dump like they had a chromium dump here during World War II,” Cope said. Josephine County produced 118,000 tons of chromite between 1917 and 1958.

At $52 a pound this week, tellurium is relatively low priced but nearly five times higher than it was in 2000. By comparison, gold is currently over $1,200 an ounce, or $19,200 per pound.

The Mystery Metal

Explaining how he fell under the spell of tellurium, Cope held up a copy of the Grants Pass Courier from March 28, 1927.

“‘MYSTERY METAL’ STIRS COUNTY” blares from the front page.

Yes, 87 years ago, a white metal created a stir for a decade before it fizzled out. Cope has unearthed a truckload of articles and documents.

March 28, 1927, the headline reads, “If it’s not tin, what is it?” and the copy reads “If it isn’t, it’s something else which might prove of equal or greater commercial importance.”

Nobody was calling it tellurium, although tellurium showed up in the news two decades earlier. The Sept. 30, 1903, edition of the Mining Review reported “ledges of tellurium” near Canyonville with ore worth $10,000 to $15,000 per ton, taken to Grants Pass for sampling.

More headlines from 1927: “Huge deposits of unknown metal draw interest to city,” “Miners staking claims,” “The excitement in Grants Pass continues to spread.”

One article described “the amalgamated order of independent tin oozers” for the men who melted the mysterious ore in their camps and made rings and cups.

In August 1927, the Associated Press reported that a laboratory was established in Grants Pass “for the purpose of making a definite study of the white metal in Josephine and Douglas counties, authorized today by William Spry, commissioner of the United States General Land Office.”

“I have gone over the samples of the metal taken out, and they look pretty good to me,” Spry said in one news story.

A full-blown investigation ensued. Besides the laboratory, Gov. Charles Martin established a mining school. The Courier also called for an investigation.

Somehow it all vanished over time. Spry died. The school left Grants Pass and turned into the geology department at Oregon State College.

Cope believes politics took mining away from Josephine County mining, with the O&C Act of 1937 playing a role in shifting the focus to timber.

“It would have changed the course of history, if they would have found the tellurium. I’m trying to start the conversation so it doesn’t go in vain.

“This has been 23 years of my life’s work. It’s still there. I guarantee it.”