Muhammad ibn Ali ibn Mahbub, from al-Abbas ibn Ma'ruf, from Hammad ibn Isa, from Hariz, from Zurarah, from Abu Ja’far عليه السلام, peace be upon him, who said: I (narrator) asked Imam عليه السلام about ‘mines, what is in them?’ – meaning khums. Imam عليه السلام said: "Everything that is rikaz (precious items buried inside the ground), then in it is the fifth (for khums)." And Imam عليه السلام said: "Whatever you process with your wealth, then in what Allah سبحانه وتعالى brings out from it, from its stones, purified, there is the fifth (for khums)."