How was Rowena Ravenclaw's diadem destroyed?

Answer:
Vincent Crabbe destroyed the diadem when he used fiendfyre (cursed fire) on it, while trying to kill Harry Potter (along with Ron Weasley and Hermione Granger).
Contributor: Imo
First answer by ID1201837433. Last edit by ID1201837433. Question popularity: 28 [recommend question].