also: いしずみ
Refers to the black mineral used as fuel. Common in industrial, energy, and historical contexts.
石炭はかつて主要なエネルギー源だった。
Coal was once a major energy source.
Coal is mined in this region.
Coal used to be mined in this area.
The factory burned coal to produce steam.
This power plant generates electricity using coal.
The truck transported the coal to the port.
coal ash; fly ash
Carboniferous period
Obsolete kana usage; marks as out-dated or obsolete.