JK Rowling's Harry Potter and the Philosopher's Stone celebrates its 20th anniversary today - and muggles across the world will be joining in on the spellbinding celebrations.

Over the last two decades the Harry Potter franchise has captured the minds of millions and the fan frenzy shows no signs of slowing down, even though the last book the Deathly Hallows was released ten years ago in 2007.

But if you've been a die-hard follower, since the beginning, then your life is about to change - we can only liken it to the day Hagrid gave Harry his Hogwarts acceptance letter.

If you're the owner of a first edition of Harry Potter and the Philosopher's Stone you could be sitting on a gold mine even Gringotts would be envious of.

The book was first published in 1997, and only 500 were printed - 300 copies went to the British Library whilst the remaining 200 went to bookstores.

At the time the publisher, Bloomsbury, had no idea how popular the story would be, which is why so few were printed. This means the books that went on general sale twenty years ago are now very valuable.

Rare bookseller Peter Harrington estimates that first edition hardbacks could be worth up to £50,000 - this is because not many hardback versions were originally printed, making them extremely rare to come across.

However paperbacks are also worth a pretty penny and could earn you a four-figure sum, one is currently on sale for £4,800 on literary website stmarysbooks.com

How can I tell if my book is valuable?

  • At the bottom of the title page the publisher must be listed as Bloomsbury
  • The date listed in the copyright information should say 1997
  • The print line on the copyright page must read “10 9 8 7 6 5 4 3 2 1”
  • The book should say it was printed in the UK, not any other country
  • On page 53 “1 wand” must be written twice in the list

But JK Rowling's the Philosopher's Stone isn't the only valuable book. First editions of the Chamber of Secrets, the Prisoner of Azkaban and the Goblet of Fire are also valuable.

A first edition paperback of Harry Potter And The Chamber Of Secrets is on sale for £4,200 on rare books seller site Shapero.

First editions of the last three books - Order of the Phoenix, the Half-blood Prince and the Deathly Hollows - are far less valuable.

If you have a Harry Potter book signed by JK Rowling herself, this could also be worth some money.