"I know for a fact that there were at least 3. A diary given to my husband for safekeeping that Mr. Potter destroyed in his second year, this cup that seems to be an artefact belonging to the house of Hufflepuff..." Narcissa said taking the cup from the folds of her robes and placing it on the table "and there is a locket, given to Regulus Black shortly before his death. If what the elf Kreacher tells me is true, it was given to him to be destroyed..."