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Footnotes in Texas History

All That Glitters is Sometimes Yttrium

This rare, radioactive material turned out to be the most valuable mineral ever discovered in Llano County

No one was exactly yelling out, “There’s yttrium in them thar hills” when the rare mineral was discovered in Llano County in the late 1880s. No one other than a few scientists and businessmen had even heard of the stuff, but it turned out to be the most valuable mineral ever discovered in the county. An ounce of yttrium sold for $144 in 1887, a year in which gold went for $19 an ounce on the London exchange.

This was also about the time that Llano County came down with a case of gold fever—despite the fact that very little gold was actually found there. The gold strike in the Klondike and the rush to Alaska were still in the news, and the prospect of a possible gold strike in Texas made people pay attention to the rocks and formations of the land.

Barringer Hill, on the banks of the Colorado River about 12 miles north of Kingsland, wasn’t at first glance a likely looking site for a jackpot. It was only about 35 feet high and unremarkable except for its unique mineral content, which made it more resistant to erosion than the granite that surrounded it. One observer who saw Barringer Hill in the 1930s said it looked like a lot of the rest of the Hill Country “except that it stood out like a sore thumb.”

A young carpenter named John Barringer acquired the hill and the land surrounding it when a Mr. Wills offered it to him in lieu of payment for a house he had hired Barringer to build. Wills probably figured a house in exchange for a bunch of rocks on a flood plain was a pretty good deal.

Barringer did a little prospecting on the hill named for him, and one day he spied an outcropping of heavy, greenish-black rock. Local geologist N.J. Badu sent samples to New York and Philadelphia for analysis. The rock was found to be composed largely of gadolinite, a radioactive yttria mineral. Yttrium minerals, because they were so rare, were extremely valuable. When shipped, it was wrapped in tissue paper and packed in iron-bound boxes.

The discovery caught the immediate attention of two of the country’s greatest inventors, Thomas Edison and George Westinghouse, who were looking for a suitable material to be used as a filament in early-day electric lightbulbs.

A young mineralogist named William Niven was sent by William Hidden, a New Jersey mineralogist with connections to Edison and Westinghouse, to Llano County to see how much gadolinite might be available there. Niven found himself in somewhat of a mineral wonderland where he discovered 47 minerals, including five that were new to science; one is named nivenite. He paid Barringer either $5,000 or $10,000 in gold (sources vary) for the hill in the name of the Piedmont Mining Company of London in 1889, but it would be several years before full-scale mining operations began at Barringer Hill.

By 1903, after Edison’s company had experimented with all 47 minerals but found no use for them, a German chemist working for Westinghouse, Walther Hermann Nernst, developed a street lamp that used raw gadolinite as a filament. Nernst, who developed the Third Law of Thermodynamics, would go on to win the Nobel Prize in Chemistry in 1920, but his street lamp only had a life expectancy of about two hours. Also, the only known sources of gadolinite were in Russia and Norway—and Llano County. Another Westinghouse engineer, Marshall Hanks, came up with a filament composed of 25 percent yttria and 75 percent zirconium. The ingredients were made into a paste and squirted into strips, baked and cut to the proper lengths. When heated, it gave off a brilliant light and increased the life expectancy of Nernst’s street lamp to 700 hours.

Today, Barringer Hill minerals can only be seen at museums, including the Llano County Historical Museum, the Texas Memorial Museum in Austin, the American Museum of Natural History in New York City and the National Museum of Natural History in Washington, D.C.

As for the actual hill, it disappeared under the dammed waters of Lake Buchanan in 1937, closing the books on one of the world’s richest deposits of rare earth minerals … but not the stories and dreams they spawned.

Clay Coppedge is a regular contributor to Footnotes in Texas History. His book Hill Country Chronicles recently was published by The History Press.