Sakuradite

Sakuradite is a rare mineral found only in the Code Geass universe. Described as the "Philosiphers Stone", it was first discovered near Stonehenge some time during the Middle Ages. Marco Polo would later journey to Japan and discover large deposits of the mineral. After Sakuradite became valuable as a superconductor, Japan would become a primary exporter of the material, and produces nearly 70% of the world's Sakuradite to this day.

Prior to its invasion and occupation by the Britannian Empire, Japan used its position as the worlds primary exporter of the mineral as a bargaining chip to exploit consumer nations and increase its own revenue. This eventually sparked the Second Pacific war, in which Japan was conquered. One of the largest Sakuradite mines was recently built on Mount Fuji, much to the dismay of Japanese nationalists.

Properties
Its form, color or composition is still unknown but it can apparently be converted and stored in liquid state, it is also highly flammable and can be used as explosive.