The philosopher's or sorceror's stone is a fantasy item that was thought up by alchemists during the Renaissance and the Age of Enlightenment. This particular substance was said to be able to turn common stones into gems, metals into gold or silver, and to be a key ingredient in the making of the Life Elixir - a potion that was said to help one become immortal. Such a stone does not exist, for transmuting metals and stones in this way is impossible, and immortality cannot be achieved.
I would suggest you look at this book with the thought that it is meant for entertainment of the fictional variety.
Good luck in future endeavors.
I agree with the previous poster as such a stone couldn't conceivably exist because if it did those who practice alchemy and could obtain such a stone would be rich, not to mention altering the physical construct of an item transmuting it from one form to another is impossible. It simply goes against the known laws of physics. I even once read a complete work of fiction where a person transformed stones to diamonds only having them to revert right back because even in that fictional world it was impossible to convert one thing to another (permanently in that case but it was fiction). Trust me if such a stone could exist many would be trying to obtain it and I would be one of them. :)
The Philosopher's Stone wasn't always a physical concept; in spiritual oriented Alchemy, it is liked to the state of God (or other divinity) or a higher state of consciousness. It's more what the stone represents, than what any physical stone could actually do.
actually the last person who posted is only mostly right.. Technically it would be possible to turn lead into gold, but the sheer amount of energy needed for the reaction does not make this a financially viable option. It would cost far more to produce the energy required than the small amount of gold is worth.
The closest thing to a philosophers stone you'll ever see, is a fusion reactor. Invent that, and you have your philosophers stone. It's just very different than they had thought it would be.
That being said, you're not becoming immortal ever, no matter how much energy you can make, it's not happening.
I actually think I read something a while back where scientists had been able to make gold or convert something to gold but it cost way more to create it than the small amount of gold was worth so it's pointless from a monetary standpoint.
TheFaceOfBo is right you can do it with a hadron collider. In a lot of the writings as EisKora said the 'stone' is not an object but a formula or equation.
Most of the idea of lead into gold comes from it being about the same weight and that one of the favs of alchemists was mercury and both lead and gold form amalgams with mercury. Two things so similar must be interchangeable but sadly it is like trying to change a duck into a swan.
Although you can turn gold into lead with an old CRT TV and a deep freeze.