'Rust' in the Bible

Therefore, this is what the Lord God says:Woe to the city of bloodshed,the pot that has rust inside it,and whose rust will not come off!Empty it piece by piece;lots should not be cast for its contents.

Set the empty pot on its coalsso that it becomes hot and its copper glows.Then its impurity will melt inside it;its rust will be consumed.

It has frustrated every effort;its thick rust will not come off.Into the fire with its rust!

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.