Unbreakable Charm

The Unbreakable Charm is a charm which makes an object unbreakable. It was used by Hermione Granger in 1994 to make a jar unbreakable, in which she placed Rita Skeeter, who was in her Animagus form at the time, to prevent her from transforming back into her human form.

Appearances
Harry Potter and the Half-Blood Prince