Chalcedony is a cryptocrystalline form of silica, very similar to quartz it also has the make up of Silicon Dioxide - however its structure is different as it is composed of very fine intergrowths of quartz and recently discovered moganite. Energetically, Chalcedony is thought to soften the energetic body in times of high stress, restoring a state of balance & calmness. When it is black in color it is said to be connected to the root chakra and is believed to help ground energy.
This Black Chalcedony also has some chunks of apophyllite crystals. It is in it's completely natural state from the earth, ethically mined in Nasik, India. It weighs 14.8 oz and measures about 5.5 x 3.5 x 1 inches.