Glitter
"There is not a spell just for making glitter. What crazy guy came up with that?" Harry asked incredulously.
"There is! Look, it says so in here!" Hermione scolded him, brandishing her heavy tome at him.
"I don't believe it!" Harry laughed, nudging her.
"Look!" Hermione pointed. Harry waved his wand dubiously, "Facere micati."
"… Oh."
"Told you it was real."