Copper

 is an ore with great usefulness because of its electrical properties.

Location
 is found deep within the ground in the Stone Caverns in small pockets.

Properties
Its electrical properties are such that it can carry electrical current for long distances with little decay in the strength.  is a requirement for many useful devices, such as Teleporters for quick travel and Sun Lights for subterranean farming.

A Miniaturizor MK II is required to mine .