2. Obsidian Tianmu Tea Bowl: It is a black glazed building in the Song Dynasty (east of Jian 'an County, Jianning Prefecture, now belonging to Jianyang District, Nanping City). It was used by Song people to fight tea. The Japanese described this bowl with the word "the universe in the bowl", saying that it seemed to be a starry sky seen by the sea in the middle of the night, which was inscrutable.
3. Black glazed oil drop bowl: one of the national treasures in Shaanxi History Museum. The _ glazed bowl has a big mouth and a small foot, and the fetal quality is gray. The whole body is covered with black glaze. The surface of the oil layer is covered with small dots of different sizes, which are called metallic luster. These dots are like oil drops floating on the water, so they are called "oil drop glaze". The oil drop glaze is a special kind of _ glaze and belongs to crystalline glaze. This is the same kind of artifacts seen so far.