Note that the whole "one place in the world" thing in manufacturing supply chains almost always means "this is the purest known natural deposit of this stuff in the world, and that makes it exponentially more affordable than any other deposit since it requires that much less chemical refining." When such deposits exist, they pretty much have total market dominance for as long as the deposit lasts, but that doesn't mean the entire industry is gone forever when that one source is gone; it's just they have to go with the next purest deposit for whatever price that comes to.
For example, right now the world's sole source of ultra-pure quartz is Spruce Pines, North Carolina. The lesser grade quartz out of here is crushed to make the pure white sand that's used to 'stock' the finest artificial beaches and golf courses for the rich. The best is critical to silicon semiconductor production; the only way to process electronic-grade refined polysilicon without contaminating it is to use fused crucibles made of this finest-grade quartz. And that best stuff comes solely from Spruce Pines; it's the world's only current commercial source of Iota 8 grade quartz, which is 99.9992% purity and sells for $10,000 a ton. For comparison, ordinary construction-grade quartz sand costs a couple of bucks per ton.
(For the silicon itself, you use high quality silica, but you *don't* use this super high purity stuff because it's pointless; you're refining silicon metal out of that silica, as opposed to the quartz crucibles which are solid silicon dioxide.)