Chemical Composition: A natural form of silicon dioxide, Chalcedony is a cryptocrystalline variety of Quartz. 

Color:  White to grey, grayish-blue, or brown ranging from pale to nearly black.  

Metaphysical:  Chalcedony is a nurturing stone that promotes brotherhood and good will. It absorbs negative energy. It brings the mind, body, emotions and spirit into harmony. Chalcedony instills feelings of benevolence and generosity. It alleviates hostility and transforms melancholy into joy. Eases self-doubt. Creates openness and enthusiasm. 

Astrological sign:  Cancer, Virgo, Sagittarius, Aquarius. 

Primary Chakra:  Sacral Chakra, Solar Plexus Chakra.