Most often appears in the comparison phrases 坚如磐石 (jiān rú pánshí, solid as a rock) and 稳如磐石 (wěn rú pánshí, steady as a rock) — used for friendships, alliances, foundations, resolve. Almost never used to literally describe a rock today.
memory
磐 (pán) shows 般 (sort/kind) over 石 (stone) — "the kind of stone" that is huge and immovable. The 石 below also doubles down on the second character of the word.
