Gemino Curse

From UnknowableWiki

The Gemino Curse is a spell that duplicates an object. Its incantation is Geminio (DH13).

It is employed by Gringotts Wizarding Bank as a security measure inside its vaults; should a thief grab something in a vault that is not theirs, the Gemino Curse will cause several copies of the object to be made, confusing the thief. Gringotts usually uses the Gemino Curse with the Flagrante Curse (DH26).

Hermione Granger also uses the spell when recovering Slytherin's Locket from Dolores Umbridge; she duplicates the locket while Umbridge is Stunned and she and Harry Potter take the real locket with them when they flee the Ministry (DH13).

It can be assumed, though it is not known, that Albus Dumbledore used the Gemino spell to create a copy of Gryffindor's sword shortly before his death, which then masqueraded as the sword while the true artifact was hidden in the office, behind Dumbledore's portrait (DH33).