Tags: Chemical Substance, Mineral.
Chalcedony /kælˈsɛdəni/ is a cryptocrystalline form of silica composed of very fine intergrowths of the minerals 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 has a waxy luster and may be semitransparent or translucent.
