Katavium

Katavium was the most strongest and 3rd heaviest non-synthetic, radioactive and/or molecular metal. It was extremely dense, having a density of 74.62 g/cm3 and its natural deposits (6-7 kg) could be naturally compressed to nearly 78 g/cm3.

Katavium was used on the Presidential Runabout for highly adequate protection against terrorism. Katavium was highly rare, occurring in only 1 or 2 planets (if lucky 3) per solar system and only in a few hundred or thousand tons.

The largest deposit was on Raro IIB1, containing 9% of its mass (449,677,593,000 t) as Katavium. The Federation had highly discrete detail on this planet, time to time even saying it was destroyed/never existed. Thus making only Commodore+ officers knowing of it's existence.

Katavium (and all other elements) were synthesizable by the Judgers.