How is buried gold extracted from the earth according to Islamic law, and what is its zakat?

The questioner did well in not accepting what sorcerers do, such as slaughtering, burning incense, and uttering incantations. These are abominations that can reach the level of polytheism (shirk), especially slaughtering for jinn. Allah commanded that slaughtering be for Him alone: ﴿Say, "Indeed, my prayer, my rites of sacrifice, my living and my dying are for Allah, Lord of the worlds. No partner has He."﴾ And He said: ﴿So pray to your Lord and sacrifice [to Him alone].﴾ The Prophet, peace and blessings be upon him, said: "Allah curses whoever slaughters for other than Allah." There is no legitimate (shar'i) way to extract a treasure other than searching for it. Jinn and devils are expelled by the remembrance of Allah, reading the Qur'an, and Surat Al-Baqarah. As for possessing the treasure, the clarification regarding it depends on the questioner explaining what he means by "the old paper."