I was looking at these the other day and wondered why these even still exists? I do a TON of crafting and still I gain them faster than I use them. I personally feel they should just be done away with OR greatly increase the amount needed to craft higher end gear. Like maybe 4 star crafts should take 10 or 12 of each cluster or something. Right now it's just 4 clusters (2 of two different kind). Big whoop..
I donno, I just feel they are pointless. They don't even sell for much either. I just give them away to whoever in my FC needs them, which is only shards for new people leveling crafting.