Bible Verses About Metals: Freed from dross by fire

Son of man, the house of Israel is become dross to me: all these are brass, and tin, and iron, and lead, in the midst of the furnace: they are become the dross of silver.

As they gather silver, and brass, and tin, and iron, and lead in the midst of the furnace: that I may kindle a fire in it to melt it: so will I gather you together in my fury and in my wrath, and will take my rest, and I will melt you down.