石炭
せきたん · sekitan · JLPT N3 · noun
coal
🪨🔥 石炭 = stone + charcoal: charcoal you dig out of the ground
石 (seki) means stone and 炭 (tan) means charcoal. Coal is charcoal that comes as stone from a mine, not charcoal made by burning wood. The same 炭 appears in 炭酸 (tansan, carbonic acid).
炭 — mountain 山 + cliff 厂 + fire 火
炭 depicts charcoal produced by burning wood from the mountainside. The top combines 山 (mountain) and 厂 (cliff/slope), suggesting the hillside source of timber, while 火 (fire) below shows the burning process. The original meaning was charcoal, later extended to coal and carbon.