Luckily like always Hermionie was happy to explain "The philosophers Stone was created by Nicholas Flamel back in the 17th century I believe. It is a huge deal in Alchemy with some praising him as achieving the pinnacle of alchemy. It allows the user to turn basic elements into gold and more importantly it produces the elixir of life. This elixir grants long life to whoever drinks it. That's how Nicholas is still around today"