lol! yeah it's a pain in the ass. Mine is 338 blast shards. Need 12 more shards in order to get that trophy); sometimes for me the shards itself appear randomly in the game. At the moment I saw there was no shard at the location I search, then when i resume tmr and went to that place again, there's a shard. I could be wrg though about it appears randomly. But the best thing to do is search the whole place. Keep on walking while pressing L3. Sometimes, you will be lucky to find one;P