Necronite Seal

Necronite Seal is a piece of ancient technology from the Ancient Empire 
The original purpose of the Necronite Seal is still unknown to this day but has become renowned for its ability to prevent decay and preserve materials almost indefinitely.
The Necronite Seal resembles a small, intricately designed amulet and is made out of an unknown metal that resembles silver but has a darker colour compared to silver, when the Necronite Seal is active there are some glowing runes, inscribed on the surface.
Scholars have not been able to figure out how the Necronite Seal works, but it works when activated by emitting a subtle, magical field that places the intended object in a form for stasis.
Due to the mysterious origins and advanced technology of the Necronite Seal, it is extremely rare and valuable. Only a few are known to exist, and they are often kept under tight security in temples, palaces, and guilds. Currently, there are only a total of 50 known to exist all over Mirateia but it's known that there must have existed a countless amount.
The first Necronite Seal discovered was discovered by accident, a sinkhole had opened up just outside a smaller town and the local guild had sent some adventures to explore the sinkhole as what looked like buildings covered the bottom of the hole, the adventuring party found that the buildings on the bottom was just a smaller part of a much larger complex of ruins and the party used the better part of two weeks exploring parts of what turned out to be a lost city from the Ancient Empire, the party on the last day of their expedition found a building were they found a crate with a assortment of items and one of these turned out to be a Necronite Seal amulet.