Durandium is a lightweight metallic alloy created from commonly available elements including large amounts of processed aluminum and a significant quantity of synthetic carbon nanotubes.
The relative toughness, cheapness, and availability of Durandium have made it one of the universe's most favored material for building vehicle frames and light starship armor. It is fairly easy for technologically-apt nations to produce large quantities of the material. Once created by a processing plant, Durandium is molded into sheets or blocks. Factories press the sheets or melt or the blocks into the desired shapes. There is also a transparent variant.
Note: May be combined with the heavier Yamataium to form the intermediate armor Yama-Dura