The Four Stones
Earth, Water, Air, Fire. All four are the top elements of the universe. So at the discovery of Sea stone, there was little thought onto the concept that there may be other stones similar to it. But that way of thinking was blown out of the thought of only myth when three stones began to show up with similar properties as Sea stone, and the ability to nullify the effects it holds.The stones come from their respective spots on the planet.
The Fire stone, held by Whitebeard, was found after a dormant volcano had erupted once more.
The Earth Stone, held by Shanks, was found uprooted from the earth after a terrible Earthquake.
Sea stone is the only stone that has an almost unending abundance, used by the government for weapons, the bottoms of their ships, and other means to hold devil fruit users.
The other three stones don't have the same effect on Devil fruit users, but when the stones are near each other, their abilities are nullified.
Four Stones(c)Jack and Val Do not use without owner permission