Prismarine

Prismarine is an underwater stone found in ocean monuments and ocean ruins. It slowly shifts colors between shades of blue and green, giving it a unique animated texture.

It can be obtained by mining with a pickaxe, crafting from Prismarine shards, or through stonecutting. Prismarine is used in construction, crafting slabs, stairs, and walls, and activating conduits for underwater breathing effects. When placed under a note block, it produces a 'bass drum' sound.