Crude coal blocks, through the hands of artisans, have become unique works with the soul of Quang Ninh mining land. As a material, wood is flexible and tough. Rock is brittle but strong. Coal is a very difficult material to handle. It was buried underground for centuries. Now coal blocks are mined up. But this material is very fragile and can be easily chipped. While creating a work, for example, a statue, if you are careless for a second, you can damage the nose and have to throw away the whole statue./.