FRESH FROM CHURCH on a cool, overcast Sunday morning in Spruce Pine, North Carolina, Alex Glover slides onto the plastic bench of a McDonald’s booth. He rummages through his knapsack, then pulls out a plastic sandwich bag full of white powder. “I hope we don’t get arrested,” he says. “Someone might get the wrong idea.”
GLOVER IS A recently retired geologist who has spent decades hunting for valuable minerals in the hillsides and hollows of the Appalachian Mountains that surround this tiny town. He is a small, rounded man with little oval glasses, a neat white mustache, and matching hair clamped under a Jeep baseball cap. He speaks with a medium‑strength drawl that emphasizes the first syllable and stretches some vowels, such that we’re drinking CAWWfee as he explains why this remote area is so tremendously important to the rest of the world.
Spruce Pine is not a wealthy place. Its downtown consists of a somnambulant train station across the street from a couple of blocks of two‑story brick buildings, including a long‑closed movie theater and several empty storefronts.
The wooded mountains surrounding it, though, are rich in all kinds of desirable rocks, some valued for their industrial uses, some for their pure prettiness. But it’s the mineral in Glover’s bag—snowy white grains, soft as powdered sugar—that is by far the most important these days. It’s quartz, but not just any quartz. Spruce Pine, it turns out, is the source of the purest natural quartz—a species of pristine sand—ever found on Earth. This ultra‑elite deposit of silicon dioxide particles plays a key role in manufacturing the silicon used to make computer chips. In fact, there’s an excellent chance the chip that makes your laptop or cell phone work was made using sand from this obscure Appalachian backwater. “It’s a billion‑dollar industry here,” Glover says with a hooting laugh. “Can’t tell by driving through here. You’d never know it.”
Rocks like these high-grade silica samples mined near Charlotte, North Carolina, are the basis for modern computer chips.
CHARLES O'REAR/GETTY IMAGES
In the 21st century, sand has become more important than ever, and in more ways than ever. This is the digital age, in which the jobs we work at, the entertainment we divert ourselves with, and the ways we communicate with one another are increasingly defined by the internet and the computers, tablets, and cell phones that connect us to it. None of this would be possible were it not for sand.
Most of the world’s sand grains are composed of quartz, which is a form of silicon dioxide, also known as silica. High‑purity silicon dioxide particles are the essential raw materials from which we make computer chips, fiber‑optic cables, and other high‑tech hardware—the physical components on which the virtual world runs. The quantity of quartz used for these products is minuscule compared to the mountains of it used for concrete or land reclamation. But its impact is immeasurable.
ABOUT THE AUTHOR
Vince Beiser is an award-winning writer whose work has appeared in WIRED, Harper's, The Atlantic, Mother Jones, and Rolling Stone, among other publications. A graduate of the University of California at Berkeley, he lives in Los Angeles.
Spruce Pine’s mineralogical wealth is a result of the area’s unique geologic history. About 380 million years ago the area was located south of the equator. Plate tectonics pushed the African continent toward eastern America, forcing the heavier oceanic crust—the geologic layer beneath the ocean’s water—underneath the lighter North American continent. The friction of that colossal grind generated heat topping 2,000 degrees Fahrenheit, melting the rock that lay between 9 and 15 miles below the surface. The pressure on that molten rock forced huge amounts of it into cracks and fissures of the surrounding host rock, where it formed deposits of what are known as pegmatites.
It took some 100 million years for the deeply buried molten rock to cool down and crystallize. Thanks to the depth at which it was buried and to the lack of water where all this was happening, the pegmatites formed almost without impurities. Generally speaking, the pegmatites are about 65 percent feldspar, 25 percent quartz, 8 percent mica, and the rest traces of other minerals. Meanwhile, over the course of some 300 million years, the plate under the Appalachian Mountains shifted upward. Weather eroded the exposed rock, until the hard formations of pegmatites were left near the surface.
Unimin's North Carolina quartz operations supply most of the world’s high‑ and ultra‑high‑purity quartz.
JERRY WHALEY/ALAMY
Native Americans mined the shiny, glittering mica and used it for grave decorations and as currency. American settlers began trickling into the mountains in the 1800s, scratching out a living as farmers. A few prospectors tried their hands at the mica business, but were stymied by the steep mountain geography. “There were no rivers, no roads, no trains. They had to haul the stuff out on horseback,” says David Biddix, a scruffy‑haired amateur historian who has written three books about Mitchell County, where Spruce Pine sits.
The region’s prospects started to improve in 1903 when the South and Western Railroad company, in the course of building a line from Kentucky to South Carolina, carved a track up into the mountains, a serpentine marvel that loops back and forth for 20 miles to ascend just 1,000 feet. Once this artery to the outside world was finally opened, mining started to pick up. Locals and wildcatters dug hundreds of shafts and open pits in the mountains of what became known as the Spruce Pine Mining District, a swath of land 25 miles by 10 miles that sprawls over three counties.
Mica used to be prized for wood‑ and coal‑burning stove windows and for electrical insulation in vacuum tube electronics. It’s now used mostly as a specialty additive in cosmetics and things like caulks, sealants, and drywall joint compound. During World War II, demand for mica and feldspar, which are found in tremendous abundance in the area’s pegmatites, boomed. Prosperity came to Spruce Pine. The town quadrupled in size in the 1940s. At its peak, Spruce Pine boasted three movie theaters, two pool halls, a bowling alley, and plenty of restaurants. Three passenger trains came through every day.
Toward the end of the decade, the Tennessee Valley Authority sent a team of scientists to Spruce Pine tasked with further developing the area’s mineral resources. They focused on the money‑makers, mica and feldspar. The problem was separating those minerals from the other ones. A typical chunk of Spruce Pine pegmatite looks like a piece of strange but enticing hard candy: mostly milky white or pink feldspar, inset with shiny mica, studded with clear or smoky quartz, and flecked here and there with bits of deep red garnet and other‑colored minerals.
For years, locals would simply dig up the pegmatites and crush them with hand tools or crude machines, separating out the feldspar and mica by hand. The quartz that was left over was considered junk, at best fit to be used as construction sand, more likely thrown out with the other tailings.
Working with researchers at North Carolina State University’s Minerals Research Laboratory in nearby Asheville, the TVA scientists developed a much faster and more efficient method to separate out minerals, called froth flotation. “It revolutionized the industry,” Glover says. “It made it evolve from a mom‑and‑pop individual industry to a mega‑multinational corporation industry.”
Froth flotation involves running the rock through mechanical crushers until it’s broken down into a heap of mixed‑mineral granules. You dump that mix in a tank, add water to turn it into a milky slurry, and stir well. Next, add reagents—chemicals that bind to the mica grains and make them hydrophobic, meaning they don’t want to touch water. Now pipe a column of air bubbles through the slurry. Terrified of the water surrounding them, the mica grains will frantically grab hold of the air bubbles and be carried up to the top of the tank, forming a froth on the water’s surface. A paddle wheel skims off the froth and shunts it into another tank, where the water is drained out. Voilà: mica.
The remaining feldspar, quartz, and iron are drained from the bottom of the tank and funneled through a series of troughs into the next tank, where a similar process is performed to float out the iron. Repeat, more or less, to remove the feldspar.
IT WAS THE feldspar, which is used in glassmaking, that first attracted engineers from the Corning Glass Company to the area. At the time, the leftover quartz grains were still seen as just unwanted by‑products. But the Corning engineers, always on the lookout for quality material to put to work in the glass factories, noticed the purity of the quartz and started buying it as well, hauling it north by rail to Corning’s facility in Ithaca, New York, where it was turned into everything from windows to bottles.
One of Spruce Pine quartz’s greatest achievements in the glass world came in the 1930s, when Corning won a contract to manufacture the mirror for what was to be the world’s biggest telescope, ordered by the Palomar Observatory in Southern California. Making the 200‑inch, 20‑ton mirror involved melting mountains of quartz in a giant furnace heated to 2,700 degrees Fahrenheit, writes David O. Woodbury in The Glass Giant of Palomar.
Once the furnace was hot enough, “three crews of men, working day and night around the clock, began ramming in the sand and chemicals through a door at one end. So slowly did the ingredients melt that only four tons a day could be added. Little by little the fiery pool spread over the bottom of the furnace and rose gradually to an incandescent lake 50 feet long and 15 wide.” The telescope was installed in the observatory in 1947. Its unprecedented power led to important discoveries about the composition of stars and the size of the universe itself. It is still in use today.
In the 1930s, Corning won a contract to manufacture the mirror for what was to be the world’s biggest telescope, ordered by the Palomar Observatory in Southern California. Making the 200‑inch, 20‑ton mirror involved melting mountains of quartz in a giant furnace heated to 2,700 degrees Fahrenheit.
THE MONTIFRAULO COLLECTION/GETTY IMAGES
Significant as that telescope was, Spruce Pine quartz was soon to take on a far more important role as the digital age began to dawn.
In the mid‑1950s, thousands of miles from North Carolina, a group of engineers in California began working on an invention that would become the foundation of the computer industry. William Shockley, a pathbreaking engineer at Bell Labs who had helped invent the transistor, had left to set up his own company in Mountain View, California, a sleepy town about an hour south of San Francisco, near where he had grown up. Stanford University was nearby, and General Electric and IBM had facilities in the area, as well as a new company called Hewlett‑Packard. But the area known at the time as the Santa Clara Valley was still mostly filled with apricot, pear, and plum orchards. It would soon become much better known by a new nickname: Silicon Valley.
At the time, the transistor market was heating up fast. Texas Instruments, Motorola, and other companies were all competing to come up with smaller, more efficient transistors to use in, among other products, computers. The first American computer, dubbed ENIAC, was developed by the army during World War II; it was 100 feet long and 10 feet high, and it ran on 18,000 vacuum tubes.
Transistors, which are tiny electronic switches that control the flow of electricity, offered a way to replace those tubes and make these new machines even more powerful while shrinking their tumid footprint. Semiconductors—a small class of elements, including germanium and silicon, which conduct electricity at certain temperatures while blocking it at others—looked like promising materials for making those transistors.
At Shockley’s startup, a flock of young PhDs began each morning by firing up kilns to thousands of degrees and melting down germanium and silicon. Tom Wolfe once described the scene in Esquire magazine: “They wore white lab coats, goggles, and work gloves. When they opened the kiln doors weird streaks of orange and white light went across their faces . . . they lowered a small mechanical column into the goo so that crystals formed on the bottom of the column, and they pulled the crystal out and tried to get a grip on it with tweezers, and put it under microscopes and cut it with diamond cutters, among other things, into minute slices, wafers, chips; there were no names in electronics for these tiny forms.”
Shockley became convinced that silicon was the more promising material and shifted his focus accordingly. “Since he already had the first and most famous semiconductor research and manufacturing company, everyone who had been working with germanium stopped and switched to silicon,” writes Joel Shurkin in his biography of Shockley, Broken Genius. “Indeed, without his decision, we would speak of Germanium Valley.”
Shockley was a genius, but by all accounts he was also a lousy boss. Within a couple of years, several of his most talented engineers had jumped ship to start their own company, which they dubbed Fairchild Semiconductor. One of them was Robert Noyce, a laid‑back but brilliant engineer, only in his mid‑20s but already famous for his expertise with transistors.
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