I was re-reading Skypeia and this page really stuck out to me. Basically, it describes the idea that the effects of seastone are the result of a special molecule called Pairopuroine.
Pairopuroine is a molecular substance that gets ejected to the air by volcano eruptions.
Now we know from Basil Hawkins that seastone originated from Wano.
But why did it originate from Wano? Well, what just happens to be at the center of Wano is the mysterious Mt. Fuji. And while we don’t know much about this mountain, we know two things.
- It’s tall enough to reach the clouds
- It’s almost 100% based off Mt. Fuji in Japan, which as we all know is an active volcano.
So my belief is that Wano created Seastone because of their location to the geographic landmark, Mt. Fuji. It’s an unusually high volcano that when it erupts, allows the citizens of Wano to capture the minerals and turn into usable materials from weapons to prison cells. With centuries of knowledge, they are the only ones capable of creating seastone.
Another interesting idea is that the Poneglyphs are also the result of this same process that seastone are made from. As we saw in Chapter 818, Nekomamushi is explaining that the Kouzuki clan created the Poneglyphs. And while they don’t describe the process, Oda actually shows it. Here is how it looks in the anime. To me, this looks like an active volcano in the background and the use of water. While I don’t know the exact process, I don’t think this is a coincidence. Both seastone and the Poneglyphs are considered indestructible so maybe they come from Pairopuroine and it’s just different densities that cause each to be so strong.
*Theory by LuffyThePirateKing