Ge Yuansheng, inheritor of coloured glaze firing skill, a national intangible cultural heritage listed in 2008, observes a piece of coloured glaze made of coal cinder at his workshop in Taiyuan, north China's Shanxi Province, March 13, 2019. Ge has been applying his skill of coloured glaze firing to waste coal cinder for five years. After going through dozens of processes, the waste material would be made into delicate artwork. (Xinhua/Cao Yang)