'Dross' in the Bible

"Son of Man, Israel has become like dross to me. All of them are like remnants of bronze, tin, iron, and lead in a furnace the dross left over from smelting silver.

Therefore this is what the Lord GOD says, "Because all of you have become dross, watch out! I'm going to gather all of you at the center of Jerusalem,

Make the pot stand empty on the coals until its bronze glows red, its rust can be scoured off, and its dross completely removed.