'Rust' in the Bible

Lay not up for yourselves treasures upon earth, where moth and rust doth corrupt, and where thieves break through and steal:

But lay up for yourselves treasures in heaven, where neither moth nor rust doth corrupt, and where thieves do not break through nor steal:

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.