you just need the HM dive. Seriously, though, I found the yellow easier than pie! I'ts not even necessary to get it, but if you are too cheap in the game to just buy a thunderstone, oh well, because that is all it is when you trade it in.
Chat with our AI personalities
Blue Shard- Route 124; Wild Pokemon. Green Shard- Route 126; Wild Relicanth. Red Shard- Route 124; Wild Pokemon. Yellow Shard- Route 126; Wild Pokemon.
you can find it on route 124 I've had a vulpix and to make it evolve i had find the red shard and i had to give it to hunter in mossdep city to get the fire stone
find a blue shard using Dive, and trade it to the guy by Mossdeep, or catch some clampearl, they hold blueshards too.
Exchange Blue Shard with the Waterstone. You'll find waterstone in Abandoned Ship, too.
to get a red shard in emerald, you have to go to route 124. Hope this helped You have to dive underwater using hm dive and find them hidden in pale couloured stones, such as those you see in caves