In the North of England flint arrowheads are traditionally known as fairy darts, fairy shot, elf arrows, saighead sidhe, gáe sídhe, or other slight variations on the same theme.
The local fairies are known for shooting darts or arrows to cause sickness in both livestock and in humans. A victim might die instantly, the point flying directly into the victim's heart without leaving an outward injury, or might simply fall ill (arthritis is often blamed on the darts). Cattle were shot for wandering into fay territory; hunters were a favorite target as they killed the deer that the fairies used for milk. Often the violent whims of the fey appear to be random, and no precipitating human transgression can be identified.
Some traditions have the fairies making the points, but unable to throw them themselves; in these cases they passed the arrows on to a mortal, either an elf or a human witch, to do their dirty work for them. In most traditions the points are the entire weapon (hence 'dart'), and were not shafted as an arrow. Some Scottish fairies, however, would shaft them with bog-reed and shoot them from a bow made out of a human rib.
A spent fairy dart was valuable, as carrying it provided the possessor with protection from fay magic and could be used to cure illness, especially illness caused by the fay. Some traditions held that later losing the point would cause bad luck -- or perhaps the loss of one's soul to the fairies upon death -- so they were carefully guarded and often buried with their owners.
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