C919Petrified wood decorated with a chalcedonian rosette and hemimorphite on a lucite base. Chalcedony is named after the ancient seaport of Chalcedon. The crystal aggregates consist of sphericalrosettes with jutting pointed crystals. It is a cryptocrystalline form of silica, composed of very fine intergrowths of the minerals quartz and moganite. Chalcedonian rosettes are rare, and information alone is hard to come by. Size: 11" high x 4" wide x 4" deep