`Sayyiduna Abu Huraira (may Allah be pleased with him) narrates from the Noble Prophet (peace and blessings be upon him) that he (peace be upon him) said: The wound caused by a well is void, and the wound caused by a mine is void, and the wound caused by an animal is void, and in minerals or buried treasure, one-fifth (as zakat) is due. (Rikaz is that treasure which is found buried in the earth).