It's rumored to be lighter than a feather. and harder than an diamond. Even in the hands of a mediocre blacksmith, it will produce superior weapons.-Ryu-Kan describing Velorium to Vyse.
Velorium is a very rare material found in-game, it is used by Ryu-Kan to forge the Vorlik Blade. This "metal" is only found in the Vortex (it's location suggest that it is a Silvite invention), and the only known two pieces are used to forge the Vorlik Blade. It is unknown how Ryu-Kan came to know of the material or it's properties, considering it's rarity and location.
To acquire the Velorium pieces the Delphinus' crane must be lowered on two specific locations in the Vortex. If the squared of the Vortex map are numbered left to right, top to bottom the pieces are found in squared 26 and 28. Once acquired they can be given to Ryu-Kan but the player must leave Crescent Isle and return before he will have it ready.