Named after an ancient city in Turkey near Istanbul (13th century), Chalcedony is a variety of quartz that can be transparent, translucent or opaque. There are many types and colours of chalcedony, some of which are covered in their own sections of this book including agate, bloodstone, chrysoprase, carnelian, jasper, onyx and sardonyx. Chalcedony was used for centuries to promote stability in the ceremonial activities of Native American Indian tribes and the Tibetans revered it as a symbol of the lotus flower. White chalcedony was given to nursing mothers to increase lactation. Stemming from the nurturing energy within the stone, chalcedony symbolizes benevolence, relieving hostilities, irritability and depression, and stimulating optimism and goodwill. The stone also promotes generosity, receptivity and responsiveness. Chalcedony is thought to bring relief from problems in the area of the throat and neck, both physical problems and those associated with using the voice, such as lecturing, etc. Chalcedony has been used to bring tranquillity to the nervous system and to dispel worrying thoughts. In addition, it is said to promote mental stability and cure various forms of dementia.