"pit or tunnel in the earth for obtaining metals and minerals," c. 1300, from Old French mine "vein, lode; tunnel, shaft; mineral ore; mine" (for coal, tin, etc,), of uncertain origin, probably from a Celtic source (compare Welsh mwyn, Irish mein "ore, mine"), from Old Celtic *meini-. Italy and Greece were relatively poor in minerals, thus they did not contribute a word for this to English, but there was extensive mining from an early date in Celtic lands (Cornwall, etc.). From c. 1400 as "a tunnel under fortifications to overthrow them."
"lay explosives," 1620s, in reference to old tactic of tunneling under enemy fortifications to blow them up; a specialized sense of mine (v.1) via a sense of "dig under foundations to undermine them" (late 14c.), and miner in this sense is attested from late 13c. Related: Mined; mining.
explosive device, by 1850, from mine (v.2).