Grey Prehnite semi precious gemstones, 20mm diameter, puffy discs. Price is per bead. Mystical Properties: Dreaming and remembrance. Enhances one's protective field. Brings peace and calm. Black Grey Prehnite is said to help clear the psyche of negative energy. Black Grey Prehnite is said to help clear the psyche of negative energy. Medical properties: Builds the immune system. Useful for anemia for blood disorders. One of the top stones available for self-hypnosis and auto-suggestion. In healing, Grey Prehnite has been used to reduce high blood pressure and control hypertension. We have recently found that