In ancient times, the source of the raw material for this thing was often a stone from a place. The stone here, rich in this thing, is an excellent choice. The craftsman picked it and shipped it to the workshop. First, break it with a huge pestle and make it into small pieces. Later, put it in a large kettle and calcined it over fire. The fire was raging, and the stone gradually melted, and the ingredients in it were mixed with each other. When the heat is good, take it out and cool it. At this time, the quality of the obtained product is pure and excellent. Its rich properties are beneficial for many purposes, and it is a rare raw material. And this stone is an important source of the required substance - calcium carbonate, which is highly prized. Only by using it as a source can you make good products and meet the needs of everyone.