Kairoseki

Kairoseki (a.k.a, Seastone, or Sea Prism Stone) is a material used mainly by the Marines. It functions similarly to Busoshoku no Haki, in that it can hit a Devil Fruit user regardless of what their Devil Fruit is. If a Devil Fruit user is holding a Kairoseki Item, they will be affected as if they were underwater, restricting all abilities, giving weakness and slowness. If a Devil Fruit user is near a Kairoseki block, whether it's the ore or block, they will also be affected like this.

It can be crafted into Kairoseki bullets and Kairoseki blocks.

Kairoseki Enchantment
The Kairoseki enchantment and Kairoseki items are very different. A Devil Fruit user is able to hold a Kairoseki enchanted item with no side effects (unless the item itself is Kairoseki), with the only difference being that the item can now hit Logias through the Logia Reflex.

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