What is the nature of the obligatory levy on minerals (Zakat or Khums/Spoil)?
Chapter on Zakat on Gold and Silver
Al-Mughni
Book of Zakat
Primary text
The required levy is Zakat. This is the position held by Umar ibn Abd al-Aziz and Malik. The evidence supporting Zakat is the tradition where the Prophet, peace be upon him, granted Bilal ibn al-Harith al-Muzani control over the Qabliyyah mines, from which only Zakat was extracted thereafter. Furthermore, it is argued that since this is a right prohibited to the wealthy of close lineage, it must be Zakat.
Supporting text
Abu Hanifa mandates that the levy is Khums (one-fifth), asserting it is Fay' (war spoils). Abu Ubayd favored this view. Those who mandate Khums cite the Hadith: 'That which is not on a frequented path, nor in an inhabited village, therein is Khums and in Rikaaz (buried treasure) is Khums,' as narrated by Al-Nasa'i and others. They also cite traditions defining Rikaaz as gold created when the heavens and earth were formed, and that Khums is due on Sayub (veins of gold and silver).