I just completed a Daily Quest, one of the "find Exotic Logs" ones, which should reward with 4 crystals.
However, after refreshing the quest screen as green tick was shaded out, completing the quest gave the animation of adding 10 gems to the top right of screen.
The gem total remained unchanged though, and checking the Purple Pimple showed an extra 4 crystals had indeed been added, so the quest does appear to have netted the correct result, but the animation clearly showed something else happening.