Unubtanium is the closest thing to a currency that exists. Once refined it can be used to power prewar weapons and technology, such as power plants.
At room temperature unubtanium is in a liquid form. Unubtanium is a unique mineral in the fact it is solid at high temperatures and gaseous at sub-zero temperatures. Unubtanium can only be mined from Stars and Planet cores.
Unubtanium is a rare resources that can only be mined in a limited number of locations in the galaxy. It traded by the vial. 1 ml of unubtainium could be compared to the dollar mark.