How the character is built
The 石 radical marks this as a solid non-metal, and that is not a coincidence of this one character — it holds right across the table. Read the radical first and the element's state at room temperature is already settled.
Mainland 硅 guī replaced 矽 xī in 1955 because 矽 was homophonous with 硒 xī (selenium) and 锡 xī (tin); Taiwan still writes 矽, read there as xì.
Where you actually meet it
硅谷 (Guīgǔ) Silicon Valley
The element itself
Silicon is the second most abundant element in the crust after oxygen, and quartz — silicon dioxide — is the mineral that survives everything, which is why beach sand is mostly quartz while the softer minerals have long since worn to clay. Turning that into a semiconductor requires purity beyond ordinary comprehension: zone refining sweeps a molten band along a bar so that impurities collect at one end, repeated until only about one atom in a billion is not silicon. A chip is, in the end, extremely well-organised sand.
Where it sits among the 118
First isolated in 1824.
In living things
Silicon is biology's glassmaker. Diatoms — single-celled algae abundant enough to matter to the whole ocean's chemistry — build two-part shells of hydrated silica, patterned with a precision that made them a favourite test object for Victorian microscopists. On land, horsetails and grasses pull dissolved silica up and deposit it as microscopic bodies called phytoliths, which is why grass will blunt a scythe, and why grazing mammals carry tall-crowned teeth that go on erupting for years as the surface wears away — though how much of that wear is the plant's own silica and how much the grit swallowed along with it is still argued about.
In Chinese history and language
Porcelain is a silicate story, and one of its ingredients handed English a loanword: kaolin is 高岭土 gāolǐngtǔ, "the earth of Gaoling", a ridge near the kilns at 景德镇 Jǐngdézhèn where the white china clay was dug. The element's own Chinese name has a quieter history — it was written 矽 xī until that proved unusable in speech, being a homophone of both 锡 tin and 硒 selenium, so the mainland standard moved to 硅 guī. It is one of the few places where you can watch a periodic table get edited for the sake of the ear.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
硅Silicon in the dictionary →Others built the same way
Every one of these carries 石, and every one is a solid non-metal.