Seastone

Biodata

Properties

• Ability suppression: Seastone weakens Devil Fruit users on contact. Its powder can also suppress them when dispersed or introduced through wounds 178 260 272.
• Hardness: A Vibranium laser cutter left no scratch on Tony’s sample; its beam scattered on contact 185.
• Effects beyond Devil Fruits: Tony’s Seastone-coated armor briefly reduced the gamma-enhanced cellular activity sustaining Abomination’s mutated form. It did not turn him back into a human 209.
• Poor conductivity: Despite its value in armor and weapons, Tony judged Seastone unsuitable for a reactor’s energy-transmission network 418.
• Limits against powerful opponents: Seastone powder weakened Kaido’s Devil Fruit power, but he tore apart a powder-laced net using Armament Haki and physical strength 265.

Sources and Control

• Wano Country: Its mines and longstanding workshops supply Seastone; its craftsmen can make fine nails and precise clasps from it 185.
• World Government: It tightly controlled Seastone circulation, mining, and processing before Eclipse seized Wano’s veins. Known uses included handcuffs, prisons, and warship hull materials 177 224 291.
• Eclipse and Stark Industries: After taking Wano, Eclipse used Udon Prison Mine for extraction and Stark Industries for processing and weapons production 291 339 416.

Uses

Restraints

• Handcuffs and shackles hold ability users; Eclipse uses adjustable grades that range from ability suppression to near-total incapacitation 177 339.
• Tony used a Seastone chain, restraint net, and heavy shackles to weaken and capture Kaido 267 272.
• Seastone discs created a restraint field that disrupted Marco’s Phoenix regeneration during his fight with Ace and Sabo 233 236.

Armor and Weapons

• Tony combined Seastone coatings with Vibranium armor. His ninety-percent-purified coating suppressed Kaido’s Devil Fruit power on contact, though Kaido’s attacks later damaged the armor 260 265.
• Eclipse deployed 3,000 standard anti-ability combat suits with ninety-percent-purified Seastone outer shells 416.
• Seastone dust in drone missiles disabled Devil Fruit users, while a Seastone-tipped electromagnetic round helped pierce a Seraphim after its defensive back flame went out 365 438.

Infrastructure

• Seastone tracks carry ore from Udon toward the Flower Capital’s smelting district 339.
• Tony incorporated Seastone composite armor into the proposed Iron Pluton warship 384.