Duanyan is precious, in addition to the stone is especially tender, pure, delicate, moist, solid, strict, made of duanyan with breath can be developed ink, ink do not damage, not frozen in winter characteristics. It is also related to the difficulty of mining and manufacturing. One party duanyan of the world, to go through the detection, digging, transportation, material selection, pu, design, carving, grinding, washing, fitting and other ten kinds of difficult and fine procedures. In the early tang dynasty in zhaoqing, guangdong (ancient duanzhou), the eastern suburbs of the antelope gorge lanke hill in the area of the end of the stream, on the basis of the production of ink-stone workers. Production of duan yan slowly became zhaoqing unique arts and crafts;