The Petrification is the catalyst of the events of Dr. Stone. The term refers to both global-scale event as well as the phenomenon itself.
Finding the cause and source of the petrification is the central conflict in Dr. Stone.
Prior to the event, lifelike statues of swallows (the small passerine bird) were being found all across the world. Senku deduced based on their distribution that they were, in fact, actual sparrows being turned to stone rather than some prank involving statues. It was also established that a few of the sparrows were still exhibiting signs of consciousness.
The Petrification Event
Some time in June 2019, all of the humans on Earth were mysteriously turned into stone statues after a greenish light swept across the land. Once the light had touched someone, their skin started to become stone-like and they'd be unable to move. The light spread across the planet fairly quickly, and did not appear to be impeded by walls or cast shadows. The six members of the International Space Station crew did not get hit by the beam despite being in orbit. Byakuya estimated from their view on the ISS and from the last updates posted online across the world that the source originated somewhere in South America. From Whyman's radio signal, Senku makes the assumption that they're mimicking the large petrification event from 2019 and assumes that the diameter used was 12,800,000 metres, slightly more than the diameter of the Earth.
- The petrification light moved like a giant wave across the horizon rather than expanding spherically like the Petrification Weapon did on a small scale.
- Enveloping the Earth took under an hour.
- The wave travelled close to the Earth's surface, approximately 20,000 metres tall.
- As its speed is constant, it was moving at 32,000km/h.
- The origin point was at 3º7'S and 60º1'W. This is the location of Manaus, Amazonas, Brazil.
The Petrification Kingdom suffered an event approximately 100 years before the current events, where Matsukaze and the other Treasure Islanders witnessed "a great number" of petrification devices falling from the sky. Almost all of them were destroyed by Matsukaze's master, but before Matsukaze could destroy the last one he was petrified, leaving the device to be used by the subsequent leaders of the Petrification Kingdom.
Currently, there seems to be no way to undo the petrification on a global scale, only individually using the Revival Fluid.
The cause of the petrification transformation on a cellular level is currently unknown, however the source of the ability to start the petrification of a body is by activating the petrification device. It is possible that there are other causes, as prior to the petrification of humans there was no mention of green light being seen around the petrified swallows. Additionally, only swallows and humans have been affected so there may be a connection between them.
Effects of Petrification
- Creatures affected by the petrification appear to be physically turned to stone, and cannot move or see.
- However, as long as the creature can stay focused and conscious, their minds can persist and they can break free once the other conditions for depetrification are met.
- Only the body turns to stone. Clothes and other inorganic items are unaffected and wear away as time passes.
- The internal organ structure of the body is retained.
- All types of injuries can be healed through depetrification. So far, it has fixed Senku's broken neck and revived him from death, cured Mirai's clinical brain death, undone Kaseki's arthritis, and healed Ginro's stab wound.
- If the body receives superficial damage through weathering, it may leave black scars. It can be fixed through repetrification.
- Being petrified increases the weight of the bodies, as was shown when Amaryllis's friends abruptly flipped the boat after getting petrified.
- Instantly heals any injuries, even to the point where the damage can be fatal.
The physical properties of the stone given are:
- Hydrophobia, therefore repels water.
- Varying hardness, with finer parts being the hardest.
- Shortwave electromagnetic radiation causes no visible embrittlement.
- X-ray fluorescence analysis shows the stone is mostly iron with trace amounts of gold. The rest is carbon and nitrogen.
- Almost completely inert, only minuscule ion discharge if nitric acid is applied.
- Dense enough to sink in water but not as dense as typical stone. Possibly porous.
All of the effects and properties of the stone put together seem to point toward healing and protecting rather than damaging the petrified creature.
Those afflicted by the petrification can be depetrified ("revived") via two known methods: a combination of maintaining consciousness and being in contact with nitric acid or alternatively being given the Revival Fluid. Senku and Taiju were the first known people to revive completely via the former method, then later the American Colony was revealed to have used the same method.
Broken statue pieces can be depetrified but doing so will result in a 'dead' part. This is fine for the bird feathers, however a completely separated arm for example will stay a gory severed arm after the revival fluid is applied. Despite this, if a statue is turned to rubble and reassembled correctly, the whole body can be revived in-tact. It is unknown what happens to the body if a statue is revived while missing a limb or other part.
It is also possible to avoid petrification by submerging body parts in revival fluid, however the whole body must be submerged or risk the unprotected parts falling off. Splashing revival fluid onto the person during the process also stops it in its tracks.
The depetrification process also sometimes results in fragments coming off the body. It appears to be due to the parts being too damaged to revert to organic parts, and sometimes pieces stay attached to the body until more revival fluid is applied directly, as was the case for Yuzuriha's foot and Senku's neck. These pieces, when fixed, can also heal any injured part they cover. If the body has not been petrified for long, the depetrification does not leave any stone fragments behind.
Pre-petrification humans that have been depetrified include:
- Senku Ishigami (via maintaining consciousness and the Cave of Miracles)
- Taiju Oki (via maintaining consciousness and the Cave of Miracles)
- Tsukasa Shishio (by Taiju)
- Yuzuriha Ogawa (by Taiju)
- Gen Asagiri (by Tsukasa)
- Yo Uei (by Tsukasa)
- Nikki Hanada (by Tsukasa)
- Minami Hokutozai (by Tsukasa)
- Hyoga (by Tsukasa)
- Homura Momiji (by Tsukasa)
- Ukyo Saionji (by Tsukasa)
- Mirai Shishio (by Senku)
- Ryusui Nanami (by Senku)
- Xeno Houston Wingfield (via maintaining consciousness)
- Stanley Snyder (via maintaining consciousness)
- Luna Wright (via maintaining consciousness)
- Carlos Barrios (via maintaining consciousness)
- Max Adams (via maintaining consciousness)
- Maya Biggs (via maintaining consciousness)
- Dr. Brody (via maintaining consciousness)
- Chelsea (via maintaining consciousness)
Post-petrification humans that have been depetrified include:
- Chrome (by Senku)
- Ginro (by Senku)
- Kirisame (by Senku)
- Kohaku (by Senku)
- Matsukaze (by Senku)
Speculation of the Cause
Senku initially had three theories about what caused the petrification:
- Aliens with advanced technology.
- A country trying to develop a weapon, which backfired.
- A new virus.
Since the discovery of the petrification device, the third theory has seems unlikely as a normal virus would take too long to change the body in any way. While the weapon theory is still viable, Senku comments that the device is "hyper-tech, beyond anything from the 21st century" and therefore may be outside the limits of any particular country's scientific capabilities. As it stands, Senku believes that the Whyman had something to do with it due to the radio signal. As Whyman's signal is coming from the moon, it leaves the alien idea more likely.
- Senku seeks the petrification device to use as a stand-in for proper modern medical procedures. (No doctor has been depetrified).
- It is shown that no matter how long a person is petrified, they will not age and remain the same until after depetrifying.
- Should Senku get a Petrification Weapon safely in his possession, he may take advantage of this to have "stone naps" to delay his aging so he can help restore modern society.
- Bad eyesight cannot be fixed by depetrification, as Kinro, and Suika and Chelsea still need glasses after their respective revivals.
- It's currently unknown if a stab wound or other mortal injury will become black marks upon depetrification or simply be sealed up normally.
- The number of years of petrification can be estimated based on the thickness of the fragments of stone left behind after depetrification, with thicker fragments meaning more time.
- Even if blood has left the body, it can still be petrified as long as it's fresh and touching the rest of the body.
- A cosmetic side effect seems to be that dyed hair can no longer return to normal, as Gen's half-white hair has persisted with no visible roots after over a year. Mirai's hair also sports a petrification scar which may prove that hair somehow gets healed in the depetrification process.
- It's possible to avoid full petrification by severing the afflicted limb before it can reach the rest of the body.
- In recent video interviews, Inagaki stated that all the threats Senku will face will be grounded in reality as much as possible, and as such the idea of aliens being the source of petrification seems unlikely. Though as the side story about Rei reveals alien life to exist. This fact along with the moon signal, and the pile of Medusa devices without any petrified people means the idea is still open.