Minecraft wiki entry for Sea_Lantern, associated text: A sea lantern can be obtained only when mined with a tool enchanted with Silk Touch. When broken using anything other than a Silk Touch enchanted tool, it drops 2–3 prismarine crystals. The Fortune enchantment increases the number of prismarine crystals dropped. This method of obtaining sea lanterns is wasteful though; the 4 prismarine shards and up to 3 of the prismarine crystals used to craft it are non-retrievable.