The idea of a Philosopher's Stone is a common one in European mythology. J.K. Rowling borrowed the idea of an alchemically created stone with magical properties for her popular Harry Potter series. In the Harry Potter books, there is only one Philosopher's Stone, created by Nicolas Flamel in the 1400s. Flamel's stone is able to transform objects into gold and produce an Elixir of Life which grants the drinker immortality.
The magical item first appeared in Harry Potter and the Philosopher's Stone, which was released under the title Harry Potter and the Sorcerer's Stone in the United States. Scholastic, the American publisher of the Harry Potter books, believed that American readers would not be as drawn to a book about a “Philosopher's Stone.” This choice has been criticized, along with the Americanization of the Harry Potter books released in the United States: small changes were made in the language that characters used out of a fear that Americans would not understand it.
The Philosopher's Stone is a crucial element of the book. Nicolas Flamel is a friend of Albus Dumbledore, Headmaster of Hogwarts School of Witchcraft and Wizardry. The two have worked together on alchemy projects, presumably working with the Philosopher's Stone itself to explore its properties. Flamel also turns to Dumbledore to keep the stone safe, and in the early part of the book, it is moved from Vault 713 at Gringotts to Hogwarts, where it is presumed to be safer.
Cooperating with several instructors at the school, Dumbledore puts a series of obstacles in the way of the Philosopher's Stone to protect it. The series of enchanted protections are designed to foil Voldemort from getting the Philosopher's Stone, as Dumbledore is concerned that Voldemort will rise again. Ultimately, Voldemort is able to penetrate all of the protections except for the last one: Dumbledore cleverly conceals the stone within the Mirror of Erised in such a way that only someone who wants to find the Philosopher's Stone but not use it can get it.
In a lesson about goals and motives, Harry gets it because he looks into the mirror with no intent to use it, and also successfully resists an attempt by Voldemort to take the Philosopher's Stone by force. After this climactic scene, the Philosopher's Stone is destroyed to prevent Voldemort from obtaining it, and Nicolas Flamel and his wife prepare for their deaths. Harry is initially concerned about the two, but Dumbledore points out that Flamel has been alive for over six hundred years, and is probably ready to pursue “the next great adventure” of death.