Proverbs 25:4
Remove the dross from silver, and it will become a vessel for the smith.
Proverbs 17:3
A crucible [is] for the silver, and a furnace [is] for the gold, but Yahweh will test hearts.
Isaiah 1:25-27
And I will turn my hand against you; I will purify your dross like lye, and I will remove all [of] your tin.
2 Timothy 2:20-21
Now in a great house [there] are not only gold and silver vessels, but also wooden and earthenware [ones], some of which [are] for honorable use, and some of which [are] for ordinary use.
Ezekiel 22:18
"Son of man, the house of Israel has become as silver dross to me; all of them [are as] bronze and tin and iron and lead in the midst of a furnace, [even] [as] silver dross, silver [dross] they became!
Malachi 3:2-3
And who [can] endure the day of his coming? And who [is] the one who can stand {when he appears}? For he [is] like a refiner's fire, like launderers' alkali.
1 Peter 1:7
so that the genuineness of your faith, more valuable than gold that is passing away, but is tested by fire, may be found to [result in] praise and glory and honor at the revelation of Jesus Christ,