The Magic of Hagstones
Hagstones make the perfect protection charms. Their watery magic will wash away all evil and negativity from your path.
Hagstones are stones that have a small hole running all the way through them. They are usually found in streams or rivers and at the seashore, where the action of running water has created the hole in the stone. It is a common belief that magic can not work on running water, and as the stones are tunnelled by the force of this element they retain its beneficial influence. This makes them good charms for deflecting away negative energies from the bearer.
Protection Stones
Hagstones are also known as Ephialtes Stones, Holy Stones, Holey Stones, Wish Stones, Nightmare Stones and Witch Riding Stones. In medieval times, they were credited with the power of protecting both people and animals from the influence of evil spirits and dark witches, and they were often worn around the neck or hung on the key or door to cattle stalls and stables. In some parts of Britian the stones were fastened to the bows of boats to safeguard the crew's voyage.
(Sourced from 'Mind, Body, Spirit')