Coral Block

Coral blocks are solid blocks that come in five variants: tube, brain, bubble, fire, and horn.

Dead coral blocks are the dead variants of coral blocks.

Obtaining
Coral blocks can only be obtained with a pickaxe enchanted with Silk Touch, otherwise, they will drop the respective dead coral block. Dead coral blocks can be obtained with any type of pickaxe.

Natural generation
Coral blocks and dead coral blocks naturally generate in coral reef structures. These are found in warm oceans.

Trading
Coral blocks can be bought from wandering traders for 3 emeralds.

Usage
Coral blocks and their dead variants can be used as building or decoration blocks.

Dead coral blocks
In order for coral blocks to stay alive, at least one of the orthogonally-adjacent blocks must be water. If placed outside of water, it will transform into its respective dead coral block after a few seconds. They are a grayscale version of coral blocks. Maximum density of living corals is reached when water blocks are a chess knight's move apart, like in a sugar cane farm.

Block data
In Bedrock Edition coral blocks have the following block data:

Trivia

 * After players had placed 10 million coral blocks underwater $$, Mojang donated US$100,000 to The Nature Conservancy to protect and restore coral reefs around the world.