defeat the small jellyfish in atlantica
you have to battle those blue things that fly around
Use the move dive to go underwater to find shards in the seaweed.
They can't be bought. You can find them underwater, or attached to wild pokemon. Chinchou have yellow shards, Clamperl have blue shards, Relicanth have green shards and Corsola have red shards.
The color shards you can find in Pokemon Platinum are Red, Blue, Green, and Yellow Shards.
you can go underground if you have the mining kit and search there and you'll find all kinds of shards.
you don't. you find them.
You first have to find them when you use the explorer kit and mine down there for shards.
find the guy who collects shards and trade shards for stones
you can find shards in ruins of alpha continuasly use rock smash on all the rocks in ruins of alpha
buy them from pickupstixs
you can find them underground