Extracted from Harry Potter Page to Screen: The Complete Filmmaking Journey.
Tom Riddle’s diary
The personal journal of Tom Marvolo Riddle, who became Lord Voldemort, was turned into one of his Horcruxes. This plain, leather-bound book was ‘broken down’ by the prop department in the same way that the costumes and other props made of leather were scratched, pounded, saturated, and stained.
Basilisk fang props were made out of different materials, depending on how they were to be used. Each fang was distressed to make it reflect the wear and tear the living Basilisk would have subjected it to.
Salazar Slytherin’s locket
The S on the front of the real locket Horcrux prop for Deathly Hallows – Part 2 is embedded with green jewels in a snakeskin pattern. Surrounding this are astrological symbols and aspect notations, which refer to the measurements of relative angles of planets to one another that are used for horoscopes. There is also an inscription inside the ring of symbols and another, longer inscription under its faceted back. The curled wire clasp of the locket continues the serpentine theme.
The Hufflepuff cup
The references that prop designer Miraphora Mina drew upon to design the Hufflepuff cup included ‘tiny golden goblets and thistle-shaped cups,’ says art director Hattie Storey. The prop itself was created by beating thin pewter over a full-sized sculpted mould, which included a bas-relief of the badger that symbolises Helga Hufflepuff’s house.
The pewter was then covered in gold paint by supervising modeller Pierre Bohanna. The cup was made for Half-Blood Prince and placed in the Room of Requirement set, but wasn’t really seen until Deathly Hallows – Part 2.
The Ravenclaw diadem
The Ravenclaw diadem was fashioned in the shape of the house’s eagle symbol. The wings of the metal eagle are encrusted with clear stones and its body and tail feathers are made of three light-blue stones.
Rowena Ravenclaw’s maxim – ‘wit beyond measure is man’s greatest treasure’ – is inscribed along the bottom of the bird of prey’s wings.