Wealth obtained from a mine is liable to?

The correct answer to this question is Khumus.

In the Islamic economic and legislative framework, wealth derived from natural resources—specifically minerals and ores extracted from the earth—is subject to a specific levy known as Khumus. The word "Khumus" literally translates from Arabic as "one-fifth," representing a 20% portion of the total wealth gained. This distinguishes it from the better-known Zakat, which is typically calculated at a rate of 2.5% on accumulated savings and specific assets held for a full lunar year.

Categorization of Extracted Wealth

Islamic jurisprudence (Fiqh) classifies wealth found beneath the earth's surface into two primary categories: Ma’adin (minerals) and Rikaz (buried treasure or ancient troves). While there are nuanced differences between various schools of law (Madhahib) regarding the exact definitions and the thresholds (Nisab) required before the tax is applied, the general consensus remains that resources extracted through mining—such as gold, silver, copper, or iron—require a portion to be set aside for the public benefit.

The application of Khumus to mines is rooted in the early Islamic period and is supported by several prophetic traditions. One of the most cited principles is the historical ruling regarding Rikaz, which established the 20% rate. Scholars have historically extended this logic to minerals extracted from the earth because, like hidden treasure, they represent a "windfall" gain that does not require the same long-term labor or agricultural cycle as trade or farming.

Khumus vs. Zakat: A Functional Difference

It is essential to understand why mining wealth is not simply categorized under the standard Zakat rules. Zakat is primarily a tool for purifying wealth that has been in one's possession for a full year (Hawl). In contrast, Khumus on mining wealth is often due immediately upon extraction or once the mineral has been refined.

Historical Implementation and Distribution

The distribution of the Khumus collected from mines followed specific guidelines. Traditionally, the revenue was used to fund public infrastructure, defense, and social welfare programs for the underprivileged, including orphans and wayfarers. This structure ensured a socio-economic balance, preventing the concentration of natural resource wealth in the hands of a small elite class.

In the modern context, while many Muslim-majority countries have transitioned to contemporary corporate taxation and mineral royalties, the classical ruling of Khumus remains a foundational topic. It highlights an early form of "resource taxation" that acknowledged the public's right to a portion of natural resources while still allowing individuals to profit from the labor and risk of extraction. Understanding this history reveals how Islamic law sought to manage natural wealth with an emphasis on immediate social responsibility and communal equity.