Chalcedony is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic. Chalcedony's standard chemical structure (based on the chemical structure of quartz) is SiO2 (silicon dioxide).
Chalcedony is a nurturing stone that promotes brotherhood and goodwill and will enhance a groups stability. It can be used for telepathy and transmission. This stone absorbs negative energy and then dissipates it so that the energy doesn't move to someone else.