Holding the ailing Frodo close, Arwen brandishes the blade in defiance of the pursuing Ring Wraiths, giving us a clear view of the sword's telltale adornments and memorable curve. Later in the film, Arwen (Liv Tyler) rushes to Frodo's aid after he is wounded with a Morgul blade on Weathertop, and we see that the sword has passed down from father to daughter.
Which brings us to Hadhafang: an arced blade that we see Elrond (Hugo Weaving) sporting on the volcanic slopes of Mount Doom during the prologue of 'The Fellowship of the Ring.' Attentive viewers will note that this isn't Hadhafang's final appearance.
