Will this happen literally, as it says?

James 5:1 Go to now, ye rich men, weep and howl for your miseries that shall come upon you.

  2 Your riches are corrupted, and your garments are motheaten.

  3 Your gold and silver is cankered; and the rust of them shall be a witness against you, and shall eat your flesh as it were fire. Ye have heaped treasure together for the last days.

Will gold actually rust in that day?

Gold normally does not rust.

For example, the gold in king Tut's tomb was apparently still shiny after thousands of years.

So will the rusting of gold be a judgment from the LORD?