The diadem is the tiara owned by Rowena Ravenclaw. It has beautiful blue crystals, which really makes this piece sparkly.
Official Sterling Silver Harry Potter Diadem Stud Earrings with Crystals
Official Harry Potter Sterling Silver Hogwarts Acceptance Letter Necklace
Official Harry Potter Rose Gold Plated Fawkes Phoenix Necklace with Crystals
Harry Potter Time Turner Spinning Gold Plated Necklace with Crystals
Official Harry Potter Gryffindor Bauble with House Necklace
Official Harry Potter Hufflepuff Bauble with House Necklace