Why it matters: Ultra-high-purity quartz is an essential component to semiconductor chips, and the only places in the world that can meet this need are two mines in a small North Carolina town. The mines' owner, Sibelco, is investing $700 million to expand capacity, but is that enough to keep up with AI-fueled chip demand? Spruce Pine is a small town about two hours drive northwest of Charlotte, NC. You can get to the general area via a number of ways, depending on your point of origin, but for the last stretch of the trip, you need to travel down...