Ermurasium

Ermurasium is a substance that appears in the anime series Sonic X. It is a rare type of metal that was once used by the people of Murasia.

Description
Ermurasium is a metal that is yellow in color, making it resemble gold.

Past
In the past, Ermurasium was used by Murasians to both create objects and supply their underground kingdom with artificial light and heat.

Homebound Saga
While on the island of the Murasians, Tanaka and Topaz stumbled upon a box made of Emurasium, which the gave to Dr. Atsumi, who identified the box as being made of Ermurasium.

Later, when Sonic and his friends entered the underground kingdom, it was noted that the artificial sky above them was being fueled by Ermurasium.