Kumsan Stone's Jangsu Gobdol is an amphibole collected at 700m above sea level in Jangsu-gun, Jeollabuk-do. It is mainly composed of Ca, Mg, and Fe, and is of a black color since it contains a little Al. It is recognized as the best quality among Gopdols produced nationwide because the crystals are dense and the color beautiful. Jangsu Gopdol emits far-infrared rays in large amounts, and it cooks food inside and outside at the same time without destroying nutrients to make its taste deep. It has high conductivity and excellent heat preservation power, so people can enjoy a constant food temperature while eating.