Copper

…a land where you will eat food without scarcity, where you will lack nothing; a land whose rocks are iron and whose hills are ready to be mined for copper.

Iron is taken from the earth, and copper is smelted from ore.

“Son of man, the house of Israel has become dross to Me. All of them are copper, tin, iron, and lead inside the furnace; they are but the dross of silver.

Just as one gathers silver, copper, iron, lead, and tin into the furnace to melt with a fiery blast, so I will gather you in My anger and wrath, leave you there, and melt you.

Set the empty pot on its coals until it becomes hot and its copper glows. Then its impurity will melt within; its rust will be consumed.

Do not take along any gold or silver or copper in your belts.

Then one poor widow came and put in two small copper coins, which amounted to a small fraction of a denarius.

…and He saw a poor widow put in two small copper coins.