Physical
As with all Quartz, Herkimer Diamonds will amplify the effect of other stones when placed next to them. An excellent stone for detoxifying the body and one which can correct imbalances in the metabolic rate.

Mental/Emotional
Mostly known as a "Stone of Attunement" Herkimers can be used to attune yourself to another person, another environment or to another activity. This makes them very useful in a practitioner/client relationship.
Herkimers are calming stones and can bring clarity of mind. They are extremely useful in helping you to recall your dreams. They enhance creativity and are very useful in releasing energy blockages when placed between Chakra points. They also help to relieve stress and tension.

Spiritual
Herkimers can help to release past life blockages. They also stimulate your psychic abilities.