Oceans are, I think, probably the blandest biome. They need some more life to them. I propose the oyster.
When an ocean chunk is generated, there is a 1/64 chance that it will be an oyster chunk. If it is an oyster chunk, 6-12 oysters will spawn in that chunk. That's it. They will not despawn, and no more can spawn. Oysters cannot move once they've spawned, but they can be moved by the player or pistons.
Oysters are .6x.6x.6 meters, making them smaller than a block. They look like... oysters. Once in a while, an oyster will open up. But it will close again in 8-16 seconds. When an oyster has been around for a while. it may develop a pearl. Each oyster can only grow one pearl. When a pearl has been grown, you will see it in the oyster when it opens up. You can then use a pick to harvest the pearl, but be careful! If the oyster closes while you are inside it, you take two hearts of damage. With the fortune enchantment, you can get more pearls than just the one from one oyster.
Pearls can be used to brew water breathing potions, and you can craft nine of them together to make a very nice looking pearl block.
You can also harvest the shell of they oyster with a pick. An oyster will drop 1-3 shell pieces, nine of which can be crafted to form a shell block, with the same texture as the oyster. Shell blocks are a tough block, and so make for sturdy construction, but are not nearly as tough as obsidian. If you break the shell without harvesting the pearl first, you get no pearl.
With silk touch, you can harvest the whole oyster, and place it as you wish. However, if you place not in water, it will remain open, and will not grow a pearl. Nice looking pearl display cases can be made by placing a block of water where you want the case, put the oyster in that, and once the oyster grows a pearl, use a piston to push a glass block through it.
Oysters can reproduce, but only occasionally. Every two minecraft days, each oyster will check to see if there is another oyster within four blocks of it, and both are underwater. If so, there is a 1/8 chance that a baby oyster will spawn somewhere within eight blocks of the parent oyster. After some time, these baby oysters grow up, and grow pearls.
So, what do you think? Answer honestly, but please be polite about it. Also, if you dislike this suggestion, please explain why, and offer any improvements you might have. If you do like this suggestion, also offer any improvements you may have.
Yeah, since the materials in question dont seem to be that useful, they shouldnt be so rare. However I do like the idea. Shell and Pearl blocks would make excellent additions to Atlantean style homes or buildings, sandstone alone is pretty bland, even with the new variants. Perhaps needs some more uses for pearls though.
Rarity, I think is one of the last things that should be decided, just because the possible uses will change over the evolution of this idea. So I will leave that for now.
Other uses could be...
Craft three oysters (obtained with silk touch (or maybe with shears?)) with a bowl to get an oyster stew. Heals 8 hunger points (four bars) and 8 hunger saturation.
Pearls could be thrown as weapons dealing 2 damage points (1 heart), making them a new sort of weapon, being fast and ranged (though not as long a range as a bow), but low damage.
Shells are pretty tough, I suppose using a shell piece as a tool could be as efficient as a wooden tool, but would not break. Or a shell could be used as a weapon that doesn't break, but does the damage of a wooden sword.
I'm not going to put these into the main post, since they're just throwaway ideas right now so as to make oysters more useful.