It could be anywhere between Mossdeep and Lilycove. The dark sea parts can be dived into but you need HM08, which is dive. Get it from Steven in Mossdeep (he's in the house at the top-left corner of Mossdeep). Just talk to him and he will give it to you. But you need to defeat the Mossdeep Gym to use dive. The Gym leaders use Psychic/Rock type Pokemon. You need a Dark or Water type Pokemon to have an advantage against them. P.S. Believe me, I had a Wailord in level 40 and I still had difficulty defeating the Gym leaders. Remember, the Gym leaders are twins so they use two Pokemon at the same time. SO put your strongest Pokemon at the top of your Pokemon list. Good Luck!
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.
Red shards are found underwater.
Use the move dive to go underwater to find shards in the seaweed.
Blue shards are found underneath the water while diving.
To get stones in Pokemon ruby you have to go to the shard hunter (surf left from Mossdeep). He will trade you stones for shards. You have to find shards by diving in the waters around route 124 (right around his house). You can use your itemfinder to find them, but they're usually just in the spots that are lighter than the surrounding area. Shards can also be found on Pokemon in the wild. The easiest way to get them is to dive, find Pokemon in the grass, and then use the move Thief on them, which will steal whatever they're holding. Relicanth- green shards Chinchou- yellow shards Clamperl- blue shards Corsola- red shards The type of stone you get from the shard hunter corresponds to the shard's color. For example, green shard=leaf stone, red shard=fire stone, etc.
The color shards you can find in Pokemon Platinum are Red, Blue, Green, and Yellow Shards.
everywhere
Catch Clamperl, Chinchou and Relicanth most of these Pokemon hold shards
they come from the clamperl
Red shards can be found all over underwater areas
The red orb is so you can find Kyogre on Ruby.
The shards are on the bottom of the seafloor along Route 124. Normally there will be on a spot that's darker than usual. Some of the shards are also in spaces between the grass. Some of the shards are also in the pokeballs you find by exploring the deep-sea troughs and resurfacing along Route 124.