Warning: Spoilers ahead for Dr. STONE Chapter 182
The Kingdom of Science has managed to create a diamond, which can be used to refuel the dreaded Petrification Device or Medusa. Dr. STONE is a manga that revolves around the concept wherein the entire planet has been petrified. Three millennia later, a super-smart high school boy breaks out of petrification and starts his journey to restore civilization and save every petrified human.
Medusa has made its manga debut in Chapter 106 when Kirisame uses it in battle. Senku and the others have fought the Petrification Kingdom, a tribe that is probably another branch of Byakuya and the other astronauts' offspring. It's then revealed that planet-wide petrification isn't just a supernatural phenomenon, it's actually caused by a machine. This consequently means that it is just right up Senku's alley and it can be explained after repeated experimentation. After all, science is all about unveiling mysteries. After the Kingdom of Science has defeated the Petrification Kingdom, Senku has finally gotten his hands on the device. However, the device has run out of juice and can't be used.
Senku and the members that aim to go to the source of petrification manages to make a ship that can't be detected on radar using the heaps of Medusa they've found. Senku has assigned the remaining members of the Kingdom of Science to study the machinery within the Medusa. In Chapter 182, Joel has finally finished disassembling it. He also finds that within all the used Medusa are blackened diamonds of the same shape and size. Those who aren't blackened are of slightly different shape. Kingdom of Science's next project has then been set.
Since Senku is part of those running with Dr. Xeno, he can only relay a set of instructions on how to create a diamond. Fortunately, it's quite easy. He tells them they only need tungsten and methanol. Both of which are readily available to them. After numerous trials and errors, they finally manage to create a diamond, which opens the possibility of having an infinite Medusa fuel.
Even though the Kingdom of Science has acquired diamond, it doesn't necessarily mean they can immediately use it as fuel for the Medusa. It's important to note that there is a certain size and shape required for the Medusa to work properly. Failing to meet these requirements will only result in having a useless piece of gem. On the other hand, Senku has almost always managed to come up with a solution to every problem that has arisen in Dr. STONE. Surely, he knows of a way to shape a tiny piece of the diamond... even during the Stone Age.