do you mean for general recipes, or just for gregtech related recipes? because i can think of 3 distinct other mod related objects that require, but do not consume empty buckets:
1. LXP absorber (liquid exp)
2. buildcraft pump (buildcraft)
3. logistics fluid basic pipe (logistics pipes)
attached are images of crafting 10 logistics fluid basic pipes with a second image of the buckets not consumed
All 3 of those things do NOT look like the bucket being supposed to be not consumed. I really hate the Crafting System...
As for the Gem Dust, use the Sifting Table.