Hardness: 6.5-7 Structure: Trigonal Zodiac: Virgo, Gemini Chakras: Root, Heart Geology: A variety of chalcedony with green mineral inclusions or dendrites of iron or manganese oxides Properties: Stability, persistence, grounding, stabilizes body systems, enhances senses Physical: Circulation, digestion, neural activity, colds, infections, flu and skin Emotional: Peaceful temperament, strong will, agreeability, persuasiveness, ego and self-esteem Spiritual: Nature Spirits, higher purpose, releases negative karma, acquire riches