The Decayed Theory of Zehra Nerezzi is a 1392 years old piece made by Zehra Nerezzi, a philosopher living in Jerusalem.
Considering its age and the quality of the work, people consider it of no value.
It is engraved with central asian patterns and some symbols pertaining to Rabbinic Judaism.
This piece doesn't exist, but as a legend. It is said that in the year 1323, Ece Nerezzi, the owner, made use of it in Istanbul / Constantinople / Byzantium to empower the Nerezzi family. Now it is lost, or broken, we will never know.