minerals and rocks; metal and stone
Refers to hard, durable natural substances; also used figuratively for something firm and unchanging, as in 金石の交わり (a firm friendship).
Many ancient metal and stone artifacts have been excavated from this area.
Their friendship is so firm it could be called a bond of metal and stone.
epigraph; inscription on metal or stone
Specifically refers to inscriptions carved on metal or stone monuments, stelae, or tablets; a somewhat literary or historical term.
The epigraph on this stone monument is difficult to decipher.
The two have kept an unbreakable friendship since their school days.
The king's achievements were carved into metal and stone and passed down to later generations.