珊瑚 can be found in the 海洋s at the ends of the world. It grows on 沙块s within 250 tiles of the edges of the map and above the depth of 0 feet. The sand must be under at least 5 tiles of water. Background walls block its growth.
It can be harvested either with a 镐, by mining out the sand underneath it, or by placing a block next to it. It can be placed as a decoration and will have one of many appearances, much like 书s. While each piece of coral only needs one block under it, it essentially takes up an extra half-space on each side, preventing walls or objects from being placed directly to either side. For example, to place 5 corals between walls, you would need the walls to be at least 11 blocks apart. To fit the same 5 coral on an open platform, it need only be 9 blocks wide.