Chalcedony, (kal SED’ uh nee) translucent, single-color

Chalcedony (kal SED’ uh nee) is a mixture of microcrystalline or cryptocrystalline quartz.  Only the translucent, single-color types of this material are sold under the name “chalcedony.” The rest of this group are sold under individual variety names such as agate or jasper.