If you have a 3Ds, you download "Pokemon Dream Radar''.
If you lose the PWT, you get a randon shard.
Do the funfest misson, "Find Shining Ores!".
Walk around in a cave and wait for a dust cloud.
I got a red shard from a hiker in the Big Stadium during baseball.
A guy in the Pokemon Center at Nimbasa City gives 10 Red Shards free.