What is the ruling on searching for earthly treasures such as gold, and is the seeker sinful?

If the place belongs to you and you are certain of the presence of a treasure within it, then it is permissible to search for it, and it is obligatory to extract one-fifth of what is found if it is rikaz (a buried treasure from the time of ignorance). However, if you are not certain of its existence, then the best course of action is to utilize the land for agriculture.

If the place does not belong to you, then permission must be sought from the state if it is state-owned, or from the private owner.