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.
A pre-modern character the naming system adopted unchanged rather than coined.
Where you actually meet it
硫黄 (liúhuáng) sulfur, brimstone — also written 硫磺
The element itself
Sulfur is the yellow crust around volcanic vents, and for a long time that is where people got it, along with a clever process that melted it underground in salt-dome caprock with superheated water and pumped it up as a liquid. That industry is essentially gone, because sulfur must now be stripped out of oil and gas before they are burned, and it comes off in such quantity that refineries produce it whether anyone wants it or not — stacked in flat yellow blocks the size of buildings in the oil-producing provinces.
Where it sits among the 118
Sulfur is one of the fourteen elements that were known before anyone was keeping records of who found what.
In living things
Sulfur enters proteins through two amino acids, cysteine and methionine, and cysteine's -SH group is the most chemically willing side chain in the whole set. Pairs of them oxidise into disulfide bonds, the covalent staples that hold secreted proteins in shape and cross-link the keratin of hair — the reason a permanent wave is a chemical process rather than a mechanical one is that it breaks those bonds and re-forms them in a new arrangement. Deeper in the cell, iron–sulfur clusters shuttle electrons through the respiratory chain; they resemble the mineral surfaces of hydrothermal vents closely enough that they are usually taken to be among the oldest cofactors in biology.
In Chinese history and language
Gunpowder came out of the elixir workshop rather than the armoury: alchemists grinding 硫磺 liúhuáng sulfur with saltpetre and charcoal in pursuit of longevity found instead a powder that deflagrated. The name they gave it never changed, and it is startlingly honest about where it came from — 火药 huǒyào is literally "fire drug", built on 药, the same character as in 中药 Chinese medicine and 药店 pharmacy. The most consequential substance in military history is, in Chinese, still filed under medicine.
The full entry
For stroke order, example sentences, audio and the complete set of meanings, see the dictionary entry.
硫Sulfur in the dictionary →Others built the same way
Every one of these carries 石, and every one is a solid non-metal.