I had one drop from a mob in Serendia Shrine.

Crafting a Yuria Blade, Axe, Longsword, or Shortsword requires a Level 4 Weapon Workshop. You can lease such workshops in Calpheon, Keplan, Glish, and Altinova. The two hardest components to acquire are the Pure Zinc Crystal, which requires plenty of zinc and Heating Skilled certification, plus Traces of Ascension, which are a low drop item for workers at the Ancient Stone Chamber excavation site in Balenos.

Note that Yuria weapons can be bought from Ronatz in Calpheon but this takes Amity to open that part of his weapon shop and it costs amity for each weapon bought meaning you have to constantly play the amity game