How to Write 矸 (gān) — Meaning “waste rock”

Imagine a dry (干) piece of stone (石) that is so useless it becomes waste rock. The image of a dry, cracked stone that nobody wants can help you link the components to the meaning of discarded mining rock.

When writing 矸, pay attention to the proportions: the left radical 石 should be slightly narrower and taller than the right part 干. A common mistake is making the 干 part too wide or forgetting that the bottom stroke of 石 is a horizontal line, not a dot.

矸 means "waste rock" and is used in mining contexts, while 矶 refers to a rock by the water (often a pier or reef). 矻 is a rare character meaning "to work hard" or "to toil," and it looks similar but has a different right side (乞 instead of 干).

矸 is most commonly encountered in the term 煤矸石 (méi gān shí), which means "coal gangue" — the waste rock mixed with coal during mining. It is a technical term used in geology, mining, and environmental discussions about how to recycle or dispose of mining waste.

Common words containing 矸 include: 煤矸石 (méi gān shí) — coal gangue; waste rock; 矸石 (gān shí) — gangue; waste rock; 矸子 (gān zi) — waste rock (in mining).