Is it permissible to go and excavate buried treasures, and is it lawful to take them if their owners have passed away?

The ruling concerning discovered treasure (kanz) depends on several details, including: the era of the treasure (pre-Islamic or Islamic), the place of its discovery (in Dar al-Harb (land of war) or Dar al-Islam (land of Islam), and whether the land is owned by someone or not), and whether the finder is the owner or someone else.

If the treasure dates back to the pre-Islamic era and bears their markings, one-fifth of it must be given [as zakat]. However, if it bears Islamic markings, it is considered lost property (luqatah).

The locations of a find (rikaz) are divided into four categories:

1. In unowned land (mawat) or land for which no owner is known: One-fifth of it must be given. 2. In land that has become his property: It belongs to him according to one opinion, while another opinion states it belongs to the original owner. The first opinion is sounder because ownership of the land does not imply ownership of the treasure within it. 3. In the property of a Muslim or Dhimmi individual: There is a difference of opinion regarding this. Some say it belongs to the owner of the house, while others say it belongs to the finder as long as the owner does not claim it. 4. In the land of war (Dar al-Harb): If it was obtained by a group, it is considered spoils of war (ghanima). If it was obtained by an individual, it belongs to the finder. There is a difference of opinion on this matter with Imam Al-Shafi'i and Imam Abu Hanifa.