Suspendium

Suspendium (부유석, Buyuseok; or " Buoyant ore") is a miraculous mineral found and used in The Tower. The higher the purity of Suspendium, the better it floats in areas of high Shinsoo density/viscosity. Pockets, Inventories and Lighthouses are all made from suspendium (Ch 40).

An item with minimal purity of Suspendium is incapable of floating by itself. A user must manipulate Shinsoo so it can float. This means the very presence of Suspendium allows an item to have a chance of floating (by Shinsoo manipulation or by itself).

The higher purity of suspendium that a item consist of, the harder it also is to control. What this also mean is that, though a high level of item often will be createt using a high purity of suspendium (making it possible to use in dense shinsoo), it also require a skilled user. And a regular will therefore often be better of with a "worse" item (made by less pure suspendium).