Is money obtained with the help of a sheikh who used the Quran and jinn considered halal after 20% (khums) has been set aside for zakat, knowing that the sheikh and intermediaries have taken their share from it?

It is not permissible to seek assistance from jinn, even for good deeds, due to the corrupting influences involved. If you discover a treasure, and it bears an Islamic mark (such as the word "Allah," or the name of a prophet or caliph, or a Quranic verse), it is considered a 'luqatah' (found item). It must be publicly announced for a year. If its owner or heir is found, it belongs to them; otherwise, it belongs to the finder. If it bears a pre-Islamic mark (such as names of pre-Islamic kings, or their images, or names of idols), then it falls into one of two situations:

1. If found on land that you own, or on permissible land not owned by anyone: One-fifth (20%) of it must be given out and spent on the same categories as Zakat, and the remainder belongs to the finder. 2. If found on land owned by someone else: One-fifth of it must be given out as mentioned above. As for the remaining four-fifths, scholars differ on whether it belongs to the finder or to the landowner. The Hanafis, Malikis, Shafi'is, and Hanbalis (in one narration) hold that it belongs to the owner of the property, while Ahmad (in another narration) holds that it belongs to the finder.