Napranium

Napranium is a soft and rare metal that collects numina. This allows mages to acquire much more magical power than they could on their own. Napranium is very difficult to work, and thus magical items are even rarer, though Poasia apparently has the ability to craft such items, and Tsouljans may too.

In The Thorn of Dentonhill, Veranix Calbert manages to come into possession of a napranium cloak and rope, which dramatically enhance his abilities.