Black agate Gemstone 15-25mm Agate is an excellent stone for rebalancing and harmonising body, mind and spirit. It cleanses and stabilises the aura, eliminating and transforming negativity. Agate enhances mental function, improving concentration, perception and analytical abilities. It soothes and calms, healing inner anger or tension and creates a sense of security and safety. Price is for one stone. Stone shape and size may vary . Sizes are approx.