The Pure Gold is a small egg-shaped golden orb that glows very brightly. However, it lost its form as it was dissolved in Bonbori's stomach, and manifested itself as a very bright light inside its esca.
It is capable of halting the aging of anyone close to it, effectively making them immortal, and the stop in aging also means the stop of any sickness spreading in the body. Even a sliver of it has an equal amount of power.
The Pure Gold is so valuable that it is said it can buy the entire world. People ranging from pirates to the World Nobles themselves want it and will go to great lengths to get it, and it is said that whoever possesses it will be brought to ruin. Additionally, the giant footballfish Bonbori is very attracted to it, and will quickly rush to consume any Pure Gold it finds when it is separated from the owner. Due to Bonbori's large size, it will also end up consuming anyone nearby, and Nico Robin believes that the saying of people being brought to ruin is referring to them being eaten by Bonbori.
The Pure Gold was created 200 years ago by Myskina Acier and Livia on Alchemi in an attempt to save their daughter Myskina Olga from a terminal illness called South Blue Emperor Fever. The Pure Gold worked, halting the onset of Olga's illness, and Olga was given a ring with a sliver of Pure Gold in it. However, people ended up hearing about the Pure Gold and going after it, which resulted in the death of Olga's mother. Olga cast her ring into the sea in anger, causing Bonbori to appear and consume the ring. However, it also consumed nearly the entire island of Alchemi in the process, including Acier, Olga, and the rest of the Pure Gold.
200 years later, Olga accidentally escaped from Bonbori's stomach with her ring in tow, but she was immediately pursued and captured by the World Government, as the World Nobles wanted her to lead them to Pure Gold. However, a treasure hunter named Mad Treasure also sought to find the Pure Gold on the orders of Gild Tesoro, and Olga escaped during a clash between the two parties. She ended up on the Thousand Sunny, and the Straw Hat Pirates offered to help her look for the Pure Gold and split the treasure. During a battle between the Straw Hats and Mad Treasure's crew, Olga's ring fell into the sea again, causing Bonbori to consume it as well as both crews.
The Straw Hats, Olga, and Mad Treasure reached Alchemi and searched for the Pure Gold, but Acier returned to his old home and stalled Treasure while Olga and the Straw Hats found the Pure Gold. However, they were separated from it as Acier blew up the mine, and Treasure claimed the Pure Gold, intending to use it to hunt for treasure forever. However, Treasure lost the Pure Gold when he was defeated in battle by Monkey D. Luffy, and it was dissolved in Bonbori's stomach acid. The entirety of the Pure Gold then manifested itself as a bright light in Bonbori's esca.
- The Pure Gold shares many similarities with the legendary philosopher's stone, as both are highly prized substances that can give the user immortality. The philosopher's stone is also a product of alchemy while the Pure Gold was created on the island of Alchemi.