Yeah I had this exact thing happen to a grow of mine a long time ago on one of my first grows. I never worked out what it was but the buds burned as if there was sulfur mixed in with it. Id only need to light it the first time and with each toke it would crackle and fire up again can't remember if it was the buds only or if the leaves did the same, I think they might have.
I put it down to 1 of 3 things, improper drying technique (used a microwave to speed things up as it was starting to mould) obviously not from this, also a few buds from the batch which were properly dried and cured over a few weeks still sparkled.
Secondly, I ended up with a spider-mite problem, I tried everything to try to stop them but with only a week to harvest I desperately used some household bug spray till the mites were dead then washed everything down with water and harvested weed tasted harsh but fine, I was thorough with the wash down, of course this was a stupid youthful mistake.
Thirdly, the strain of the weed no idea what it was, it was just bagseed. I was still convinced that the sparkling was due to the bug spray until I saw your post as I had never heard of sparkling buds besides mine.
I grew in unsterilized cheap potting mix with some osmacote, under a 400w HPS and only used aquasol as an additive to the water and a few times added some superthrive. I flushed the grow over a week as best I could but I doubt my sparkling was from nutes (unless foliar feeding with nutes which I never did).
I have completed many grows since and regardless of drying/curing methods or flushing techniques have never had a sparkling mix again Ive never used bug spray since so I figured it was either that or the strain.
