Silicon
Silicon, smelted from quartz, alloys steel and aluminium, makes silicones, and in ultra-pure form underpins solar panels and chips.
Steel & alloying · No. 20
- EU strategic
- EU critical 2023
- US critical 2025
- India critical 2023
Chip-grade silicon starts as ordinary quartz rock and ends up with just one stray atom per ten billion.
Chart: Illustration: Silicon
Where it comes from
Chart: Map of where it comes from
Silicon is never mined as metal. Producers quarry pure quartzite and strip out the oxygen with carbon in huge electric arc furnaces, using a great deal of electricity.
Three things to know
- Silica makes up about two-thirds of the Earth's upper crust by mass, so geology is never the problem.
- China made about 4.0 of the world's 4.6 million tons of silicon metal in 2025.
- In April 2025 Chinese silicon metal prices sank to their lowest since November 2016.
The journey
- 1 QuartziteHigh-purity silica rock, SiO2
- 2 Arc furnaceReduced with coal, coke or wood
- 3 Metallurgical silicon98-99% pure, or ferrosilicon
- 4 PolysiliconSiemens process purifies it further
- 5 WafersIngots sliced for solar cells, chips