Purple Jasper stimulates the crown chakra. It eliminates contradictions. Purple is also a colour that will connect you with your spiritual self. It is good for mental & nervous problems. It will assist very well with rheumatism & epilepsy. Helps with pain, is used in deep tissue work & helps heal the bones. Too much purple & you don't tend to live in this world.
This makes them very good charms for deflecting away negative energies from the bearer. Hag stones are also known as Ephialtes stones, Holy stones, Holey stones, Wish stones, even Donuts. Nightmare stones and Witch Riding stones. In medieval times, they were credited with the power of protecting both people and animals from the influences of evil spirits and were hung around the neck or on the key or door to cattle stalls and stables.
The most interesting quality that Hag stones possess is the perceived ability to enable the bearer to see fairies and be protected from their enchantments. Such a charm would have been especially useful at Samhain, when the veil between this world and the fairy world thins.