Semiconductor’s Reliance on North Carolina

On September 26th, 2024, two mining companies in the Appalachian foothills of North Carolina closed their gates ahead of Hurricane Helene. What followed was more than 20 inches of rain, floodwaters that tore out over 30 miles of the region's only rail line, and a brief, genuine scare that the global semiconductor supply chain was about to seize up.

The floodwaters destroyed long stretches of the CSX rail line that is the primary route for transporting material out of the mines. The material at risk was high-purity quartz, mined from a single American mining district called Spruce Pine.

Spruce Pine supplies an estimated 70 to 90 percent of the world's high-purity quartz used in semiconductor manufacturing. According to industry experts, there is no known alternative source at the purity level chipmakers require. High-purity quartz is refined into a crucible, then used to hold molten silicon in a process called the Czochralski method.

A single silicon ingot grows out of that melt, then gets sliced into thin wafers, which is the base layer every chip is built on. From there, those chips end up in nearly every piece of consumer electronics: laptops, smartphones, cars, and beyond.

(the two high-purity quartz mines in North Carolina)

Who owns the mines? Two companies.

These two mines belong to Sibelco and The Quartz Corp. Sibelco is a privately held company with roughly 5,000 employees, headquartered in Antwerp, Belgium. The Quartz Corp is a private joint venture between Imerys (the French mining and minerals group, roughly 13,700 employees) and Norsk Mineral (a small, family-owned Norwegian holding company).

Both operate in Spruce Pine, a town of 2,200 people in Mitchell County, tucked into the Blue Ridge Mountains of western North Carolina. A Spruce Pine council member said that an estimated three-quarters of the town has a direct connection to the mines, whether through a job, a job that relies on the mines, or a family member who works at the facilities.

It is worth being precise about what, exactly, was at risk during the Helene storm. "High-purity quartz" is used to create "high-purity silica sand". This sand, made up of silicon dioxide, is used to create the crucible. What separates a semiconductor crucible from an everyday product like glass is not the mineral itself but the purity tier applied to it. Ordinary glass makers, unlike chipmakers, have plenty of alternative silica sand sources around the world and are not dependent on Spruce Pine the way semiconductor manufacturers are.

The tier that is genuinely scarce, and growing fastest, is the ultra-high-purity grade: China alone consumed 63% of the world's high-purity silica sand in 2024, almost all of it for solar panels.

Semiconductors rely on this two-mine bottleneck

The crucibles that the high-purity quartz sand gets melted into, to grow the silicon ingots that eventually become wafers, last just 300 to 400 hours before they need replacing. The global high-purity silica sand market was worth $12.4 billion in 2025, headed to $22 billion by 2034. Recycling offers little help either, glass cullet (crushed recycled glass) can replace only 15 to 25% of virgin high-purity silica in premium applications.

Since the semiconductor industry is not only critical but also a strategic priority for U.S. reshoring efforts, it would seem the U.S. should stockpile this material. The U.S. does stockpile other key strategic resources through the National Defense Stockpile. The Defense Logistics Agency does list quartz as a strategic material, but it is specifically a lab-grown, cultured quartz used for radio and guidance-system oscillators, not the natural high-purity quartz that underpins crucible manufacturing for semiconductors. On the material that actually controls the chip supply chain, the government has no dedicated reserve at all.

Today, two private, foreign-owned companies control the material sitting underneath the country's semiconductor ambitions, with no strategic backstop in place.

Could the U.S. seize the mines, if needed?

The U.S. has seized private industry before, but always through Congress, not presidential fiat. We saw this in World War I with railroads and telegraph lines, and then again in World War II with coal mines, railroads, trucking, and weapons manufacturing. This was also done in 1925 with a full legal monopoly over helium extraction, yet all of these ran through specific acts of Congress.

The one time a president tried to skip that step was in 1952 when President Truman seized the steel mills during the Korean War. The Supreme Court quickly struck it down, ruling that national security alone does not give a president the authority to take private property without congressional backing. That precedent has held for over 70 years.

Modern administrations do not seize industry assets, instead there is a path through Congressional approval by using the Defense Production Act (1950). This allows the government to force companies to prioritize government contracts and these purchase orders are then funded by the government. President Biden invoked it in 2022 for lithium, cobalt, nickel, graphite, and manganese, not by taking over any mine, but by funding new domestic capacity and locking in purchase agreements. President Trump used it during COVID to order General Motors to build ventilators. Neither case involved the government actually operating or owning a private facility.

Takeaway: The Helene storm in 2024 caused a washed-out rail line in a town of 2,200 people to briefly put the global semiconductor supply chain at the mercy of two private, foreign-owned mining companies. These two mines supply 70-90% of the global high-purity quartz market, a required material for the $1T semiconductor industry. Both mines draw from the same quartz deposit in the foothills of North Carolina, and this mineral concentration risk is not backstopped by a strategic reserve, even though the U.S. stockpiles other materials that are far less critical. The bottleneck hinges on one deposit and two mines, and it underpins a market that depends on crucibles being replaced every few hundred hours, with no substitute supply in sight.

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