Originally during the GoD expansion raw pale nihilite and raw shimmering nihilite were dropped exclusively in Taelosian zones. There are several jewelcraft and smithing combines dependent on jewelcraft that require the drops to use. After raw pale nihilite was renamed to raw crimson nihilite and both types were migrated to all enemies of the appropriate level ranges, I'm guessing an internal change was made that caused the drops from the GoD mobs to no longer be linked to the expansion. You can easily confirm that the material is from the correct era by looking at the jewelcrafting npcs in abysmal sea (or checking eqtraders recipe list for GoD) It is the refinement recipe/handing similar to taelosian wheat, taelosian tea, etc. For jewelcrafting, but in sufficient farming to get largue quantities of all the other unrefined items, the two types of nihilite currently don't seem to drop.