Horcrux

A Horcrux is an extremely Dark magical object. Described in Magick Moste Evil as "the wickedest of all magical inventions", it is defined as any object which contains a part of someone's soul. To split one's soul, one must commit the supreme act of evil – murder. Then, by casting a spell (incantation not yet known), the murderer is able to encase a portion of their soul inside the chosen object.

The process violates two laws of nature, stating namely that Man must not kill another of his own kind, and that the soul should remain whole and intact (notice that the part of soul which is still in the body is not destroyed, but become an errant spirit). These violations gives the Horcrux its reputation as the most evil magical object. Horcruxes are therefore a banned subject at Hogwarts, and possibly elsewhere, too. Voldemort, obsessed with immortality, was prepared to find those few people who knew about the Horcrux and the incantation needed to create it, and then kill, to be able to immortalize himself.

Dark wizards usually choose objects of great importance to them as future Horcruxes. This might be symbolic of Muggles who are so greatly attracted to an object that after they die, they are bound to the physical world by the object, and thus cannot progress to the afterlife.

Voldemort is known to become less and less human with each divison of soul. It is unknown whether it cause his apparence evolution, because his appearance remains the same until he reappears to ask Dumbledore for the defense against the dark arts job. But it is possible he used magic to hold his human apparence until this, and later became a ugly figure when he unmasked himself, as Emperor Palpatine of Star Wars fame did.

List of Horcruxes
Albus Dumbledore and Harry Potter believe that Voldemort used as many as 6 Horcruxes to hide parts of his soul. Notice that he never had six horcruxes at once because the diary was destroyed before Nagini was turned to an horcrux. But Voldemort didn't know about the diary destruction when he used the spell on Nagini.

Horcruxes

 * Harry Potter, or his scar &mdash; It is possible that Harry became Lord Voldemort's fifth Horcrux when Voldemort killed Lily Potter. This could explain why Harry is a Parselmouth, and why he was sometimes able to read Voldemort's thoughts. (Chamber of Secrets - Dumbledore: "Unless I'm much mistaken, he transferred some of his own powers to you the night he gave you that scar. Not something he intended to do, I'm sure ...") The major support for this theory is that Dumbledore is very precise on each Horcrux, and very blurry on the fifth ("something from Ravenclaw or Gryffindor"). Some fans have identified this as a lie like Obi-Wan Kenobi's subtle meaning for "Darth Vader killed your father" from the original Star Wars Trilogy. However, it's not even a full lie, as Harry symbolizes Godric Gryffindor's virtues. This theory raises other questions: is there a link with Harry's blood used to resurrect Voldemort? And with Dumbledore's gleam of triumph when he heard this?
 * However there are 3 major problems with this theory:
 * Voldemort wouldn't have tried to kill Harry that night if he planned to make him a Horcrux and a spell like that could not have happened by accident.
 * If Harry is a Horcrux, Voldemort would have known and would not have made any attempts on his life.
 * Voldemort would have had no time to cast the spell needed for Harry to be a Horcrux. He tried to kill Harry almost immediately after he killed Lily.


 * The Sorting Hat &mdash; as an object which is a close part of Hogwarts, originally belonging to Godric Gryffindor and having a part of each house of Hogwarts in it, this is a possible Horcrux. JK Rowling has disputed this theory on her website.
 * Tom Riddle's Hogwarts Award for Special Services to the school.
 * Voldemort's wand
 * Wormtail's silver hand
 * The Mirror of Erised: its "clawed feet" suggest the eagle symbol of Ravenclaw.
 * Goblin-made tiarra belonging to Molly Weasley's Aunt Muriel (since it would symbolise Voldemort's desire to be a supreme ruler)
 * The cursed opal necklace (opals and ravens have certain features in common)

Important note: the majority of the fans see Harry or another of these instead of "something of Ravenclaw's or Gryffindor's" to reach the number 6. Few think there could be more than 6 Horcruxes.

Locket's fate
See Salazar Slytherin's Locket

Locations
Known Horcrux locations are that Tom Riddle's diary was left with Lucius Malfoy and Gaunt's Ring was left hidden magically within the ruins of the Gaunt House.

Possible locations for the other Horcruxes include
 * If the Locket is the one that Harry and the Weasleys came across in 12 Grimmauld Place, then it might be in the possession of Kreacher, it may have been stolen and sold by Mundungus Fletcher or it may still be at the Headquarters of the Order of the Phoenix. Note: R.A.B. may have made it no longer a Horcrux in some way.
 * If Voldemort created a Horcrux when he killed James Potter, then the Horcrux may still be in that same house at Godric's Hollow. The suggestion at the end of HBP that Harry intends to visit the house in Harry Potter and the Deathly Hallows supports this possibility.
 * The Chamber of Secrets. A location of significance to Voldemort.
 * The Orphanage. A location of significance to Voldemort.
 * The Riddle House. A location of significance to Voldemort.
 * The trophy room at Hogwarts. Voldemort likes to collect trophies and has his own trophy there.
 * In the possession of a Death Eater. This is implied in HBP, where Bellatrix Lestrange states 'The Dark Lord has, in the past, entrusted me with his most precious- if Lucius hadn't-' although this may just refer to the already destroyed diary.
 * Room of Requirement: the place where every student hides dangerous artifacts
 * The Lestrange Vault in Gringotts.

Murders

 * The ring: believed to have been created from Voldemort's father's and grandparents' murders.
 * The diary: unknown; Moaning Myrtle has been suggested, but she is unlikely: a snake is not exactly a weapon, so Voldemort didn't really kill her by himself.
 * The cup: unknown, as Hepzibah Smith is not a significant murder (or maybe she is, as Helga Hufflepuff is her very ancestor)
 * The locket: same as the cup (in all cases, Hepzibah is only usable for one Horcrux)
 * Nagini: Frank Bryce (Dumbledore implies it; it is strange to call a Muggle an "important" murder, but he's Voldemort's first murder from his new body)
 * Harry Potter: Lily Potter or James Potter
 * Voldemort's wand or Wormtail's hand: Cedric Diggory (but it would mean you can create an Horcrux by giving orders to murder)
 * The Mirror of Erised: Professor Quirrell (as Voldemort sacrificed him)

Note: Tom stole the ring before he interviewed Slughorn about Horcruxes, but he interviewed him about creating more than one horcrux, so the first could have been created before. The chronology of Tom's last year is unclear: we don't know if he interviewed Slughorn before or after releasing the basilisk (anyway, the main topic in Slughorn's interview was the power of the number seven, so it is even possible he created two horcruxes before the interview).

Horcruxes outside of the Harry Potter universe
The term "Horcrux" is author J.K. Rowling's invention, though its similarities to other words manage to evoke suggestions of horror, pain, and alienness. However, the concept of a soul container is not original to the world of Harry Potter. The idea of concealing one's soul in an external object to gain immortality has appeared in the mythology of many cultures and dates back thousands of years. The tales of Koschei the Deathless from Russian mythology are examples of such items existing in myth. Further examples exist in Indian folk-tales, where evil sorcerers evade death by sealing their spirit inside parrots, becoming invulnerable until someone destroys the parrot. Sauron's ring doesn't contain his soul, but like Horcrux, it prevents him from being killed while the artefact isn't destroyed.


 * Sauron's Ring in the Lord of the Rings trilogy
 * Morda's shard of bone in Taran Wanderer
 * Koschei
 * Lich, specifically the phylactery