Upon whom is the Khums (one-fifth share) obligatory when Rikaaz (buried treasure) is found?

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The Khums is obligatory upon everyone who finds the Rikaaz, regardless of whether the finder is a Muslim, a Dhimmi (non-Muslim subject), a free person, a slave, a Mukatab (a slave contracted for freedom), an adult, a minor, or insane. The general principle is that the remainder belongs to the finder. If the finder is a slave, the treasure belongs to the master, analogous to gathering firewood or hunting. If the finder is a Mukatab, he owns it, but the Khums is due. If the finder is a minor or insane, the treasure belongs to them, and their guardian manages it. This is the position of the majority of scholars. The evidence is the general statement of the Prophet, peace be upon him: "And in Rikaaz is one-fifth." This implies the obligation of Khums on all Rikaaz found, and that the remainder belongs to the finder, whoever they may be. Furthermore, it is property whose owner is a non-believer, thus the Khums is due upon the finder, and the remainder belongs to the finder, similar to spoils of war (Ghanimah). Finally, since it is an acquisition of wealth, it belongs to the acquirer if free, or to the master if a slave, like gathering firewood or hunting.