Is it permissible to excavate Roman buried treasure found in Grandmother's house, and is Zakat obligatory upon it?

The buried treasure known as Rikaz (that which was buried by the people of Jahiliyyah) requires one-fifth to be given as khums, based on the Prophet's (PBUH) saying: "And in Rikaz is the fifth." As for the remainder, there are two opinions: does it belong to the finder or to the owner of the house?

The first opinion: It belongs to the owner of the house. This is the view of Abu Hanifa and Muhammad ibn al-Hasan, and Abu Yusuf found it preferable.

The second opinion: It belongs to the finder. This is the view of al-Qadi from the Hanbalis, and al-Hasan ibn Salih and Abu Thawr.

If you extracted the Rikaz with the permission of the house owner, you are entitled to a customary wage (ajr al-mithl) if no specific wage was agreed upon. If it was without his permission, you are not entitled to anything. The owner of the house is then responsible for giving out the fifth. However, according to the Hanbalis, the Rikaz is yours after giving out its fifth, even if you were an employee, unless you were hired specifically to search for and extract it, in which case it belongs to the one who hired you.