Locket of Slytherin

• Type: Heirloom, Horcrux
• Owners: Salazar Slytherin, The Gaunt family (Marvolo Gaunt, Merope Gaunt), Caractacus Burke, Hepzibah Smith, Tom Riddle (Lord Voldemort), Kreacher, Mundungus Fletcher, Dolores Umbridge, Harry Potter, Ron Weasley, Hermione Granger
• Maker: The locket itself was an heirloom of Salazar Slytherin. Lord Voldemort transformed it into a Horcrux.

The Locket of Slytherin is described as a heavy, oval-shaped locket made of gold, roughly the size of a hen's egg. Its most prominent feature is a large, ornate serpentine 'S' inlaid with small, glittering green stones on its surface. The locket's chain is also made of gold. When opened, it reveals two glass windows, meant to hold pictures. As a Horcrux, one of these windows contained a silk lining, and behind the other was the watching eye of Tom Riddle. The locket could only be opened by someone speaking Parseltongue.

As an heirloom of Salazar Slytherin, the locket's primary known magical property was its Parseltongue-activated clasp. This ensured that only a descendant of Slytherin or another Parselmouth could open it. Its far more potent and dangerous properties came from its transformation into one of Lord Voldemort's Horcruxes.

• Soul Fragmentation: It contained a fragment of Lord Voldemort's soul, anchoring him to life and making him immortal as long as the locket remained intact.
• Malevolent Influence: The locket exerted a powerful, corrupting influence on anyone who wore or carried it for an extended period. It amplified negative emotions, paranoia, and suspicion. When worn by Harry Potter, Ron Weasley, and Hermione Granger, it caused them significant emotional distress and led to a major conflict that temporarily drove Ron away from his friends.
• Psychological Warfare: The soul fragment within the locket was semi-sentient and could actively defend itself. When Ron Weasley attempted to destroy it with the Sword of Gryffindor, the Horcrux produced dark, spectral images of Harry and Hermione, preying on Ron's deepest insecurities to dissuade him. It spoke in Voldemort's voice, taunting him about being least loved and a second-best.
• Defensive Enchantments: The locket was extremely durable and could not be destroyed by conventional magical or physical means. It required a substance of immense destructive power, such as Basilisk venom or Fiendfyre, to be vanquished.

1. Heirloom of the Gaunts: The locket was a prized possession of Salazar Slytherin and was passed down through his direct descendants, the Gaunt family. By the 20th century, it was owned by Marvolo Gaunt, who cherished it as a symbol of his pure-blood heritage.
2. Sale and Acquisition: After her father and brother were imprisoned in Azkaban, Merope Gaunt stole the locket. Abandoned by her husband, Tom Riddle Sr., and desperate for money, she sold it to Caractacus Burke at Borgin and Burkes for a mere ten Galleons. Burke later sold the locket to a wealthy, elderly witch named Hepzibah Smith.
3. Theft and Horcrux Creation: A young Tom Riddle, working at Borgin and Burkes, visited Hepzibah Smith and learned of her two greatest treasures: the locket and Hufflepuff's Cup. He murdered her, framed her house-elf Hokey for the crime, and stole both artifacts. Voldemort later turned the locket into a Horcrux after murdering a Muggle tramp.
4. Concealment in the Cave: Voldemort hid the locket in a secret seaside cave from his childhood. He protected it with a series of powerful enchantments: a blood-toll to enter, an enchanted boat that would only carry one wizard, a basin filled with the Drink of Despair, and an army of Inferi in the surrounding water.
5. The Regulus Black Deception: Regulus Black, a young Death Eater, learned of Voldemort's Horcruxes and defected. Accompanied by his house-elf Kreacher, he journeyed to the cave. Regulus drank the potion himself to spare Kreacher, swapped the real locket with a fake one containing a note to the Dark Lord, and ordered Kreacher to take the real locket and destroy it. Regulus was subsequently dragged to his death by the Inferi.
6. At Grimmauld Place: Kreacher was unable to destroy the powerful Horcrux and kept it hidden in a cupboard at Number Twelve, Grimmauld Place for years. During a clean-out of the house by members of the Order of the Phoenix, the locket was found but discarded. It was then stolen by Mundungus Fletcher.
7. Possession by Dolores Umbridge: Mundungus Fletcher was caught selling stolen goods by Dolores Umbridge, a Ministry of Magic official. She confiscated the locket from him as a bribe to avoid prosecution. Unaware of its true nature, Umbridge wore it as a status symbol, claiming the 'S' stood for Selwyn, a pure-blood family she falsely claimed ancestry from.
8. Retrieval and Destruction: Harry Potter, Ron Weasley, and Hermione Granger learned of the locket's whereabouts from Kreacher. They infiltrated the Ministry of Magic and successfully retrieved the locket from Umbridge. After months of carrying the cursed object, Harry discovered he could open it with Parseltongue. In the Forest of Dean, Ron Weasley destroyed the locket using the Sword of Gryffindor, which was imbued with Basilisk venom, silencing the soul fragment within forever.

The Locket of Slytherin is a central object in the latter half of the series, particularly in Harry Potter and the Deathly Hallows. It represents Voldemort's pride in his Slytherin ancestry and is a physical manifestation of his fragmented soul and lust for immortality. The search for and destruction of the locket drives a significant portion of the trio's quest. The object itself serves as a source of immense conflict, testing the friendship between Harry, Ron, and Hermione to its limits. The history of the locket also introduces the tragic and heroic story of Regulus Black, providing a powerful narrative of redemption and courage that contrasts sharply with Voldemort's evil. Its destruction is a critical turning point and a defining moment of bravery for Ron Weasley.

• In the film adaptation of Harry Potter and the Deathly Hallows – Part 1, the locket's Horcrux manifestation is more visually explicit. It creates spectral, silver versions of Harry and Hermione who kiss passionately to taunt Ron, rather than the book's description of shadowy figures with Voldemort's voice. (film)
• The film also depicts the locket actively trying to pull Harry down and drown him when he dives into the frozen pool to retrieve the Sword of Gryffindor, an embellishment of the book's events. (film)