The silver goblets are items of treasure found within the Lestrange Vault at Gringotts Wizarding Bank. They are described as part of a vast hoard of valuable objects, including mounds of gold Galleons, silver platters, and suits of armor. Like the other treasures in the vault, the goblets are enchanted with powerful defensive curses from the field of Dark Arts.
The primary function of the silver goblets, along with all other treasure in the Lestrange vault, is to act as a security system. They are bewitched with two potent curses that activate upon contact:
The combination of these two curses creates a deadly trap. An intruder who touches a single item will be burned and then quickly buried or crushed under a deluge of worthless, red-hot duplicates.
The goblets are part of the ancient wealth of the Lestrange family, a notoriously dark pure-blood wizarding family. They were stored deep within the family's high-security vault at Gringotts. After Lord Voldemort entrusted Bellatrix Lestrange with one of his Horcruxes — Helga Hufflepuff's Cup — the entire contents of the vault, including the silver goblets, were enchanted with the Gemino Curse and Flagrante Curse to serve as a formidable defense for the piece of his soul.
The silver goblets play a significant role as a dangerous obstacle in Harry Potter and the Deathly Hallows. When Harry Potter, Ron Weasley, and Hermione Granger break into the Lestrange Vault in 1998 to find and destroy the Horcrux, they trigger the curses. Upon accidentally touching a piece of treasure, the trio is nearly overwhelmed as the vault begins to fill with a suffocating avalanche of burning-hot copies of goblets, coins, and platters. The goblets and other items serve as a physical manifestation of the Lestranges' greed and cruelty. Harry Potter ultimately uses the Sword of Gryffindor to retrieve the real cup from a high shelf, bypassing the cursed treasure on the floor, while Griphook the goblin takes the sword in return for his help.
While the most prominent silver goblets in the series are the cursed ones in the Lestrange vault, other silver goblets appear on occasion. Albus Dumbledore conjures two silver goblets when he first meets Tom Riddle at the orphanage, and a silver-topped jug and goblets are seen at Shell Cottage. This suggests that silver is a common, if valuable, material for such items in the wizarding world. In the film adaptation of Harry Potter and the Deathly Hallows – Part 2, the visual effect of the Gemino Curse is shown in dramatic detail, with the treasure, including many goblets, multiplying at an explosive rate and nearly drowning the main characters (film).