Silicon Metal After an hour by truck, the quartz mini-boulders arrive at Sabón, Ferroglobe’s 125,000-square-meter factory in the coastal province of A Coruña. The result is silicon metal and carbon monoxide. Fact: 3.8 million tonnes of silicon metal was produced in 2023, according to the U.S. Geological Survey. Purified Polysilicon The resulting silicon metal is about 98 percent pure, and that’s not good enough. Silicon Wafers The ultrapure silicon is made up of many crystals at different orientations.