Engetsite
Engetsite is a bluish crystal-like metal which is typically found on Engetsu-san (the mountain it was named after), but can sometimes be found in other places throughout Yuriba. The metal itself is equal in malleability as gold, yet has a lower conductivity than most common metals. The only property that makes this metal stand out aside from its appearance is the fact it glows blue in the presense of magic.
Engetsite saw use in the Lily Civilization as a magical means to light temples, though information on how wide-spread the usage was is currently lacking. There is the suggestion that it may have had a connection to the goddess Engetsu, due to where the metal is found and its color, but nothing survives to substantiate this.