Rust

Instant, G (1)
Counter target activated ability from an artifact source. (Mana abilities can't be targeted.)¹
"How dull it is to pause, to make an end,/ To rust unburnished, not to shine in use,/ As though to breathe were life!" -Alfred, Lord Tennyson, "Ulysses"
Illus. Liz Danforth

Gatherer Card Rulings [Nov 2009]

• 10/4/2004: Can't be used on mana abilities because they don’t use the stack.  They’ve already resolved by the time you get priority.

Format Legality	Legal in Vintage, Legacy Banned in Extended, Standard, MTGO Classic
Printings (1/2)	Legends (Common (C2))