as we can see from the calcium carboate

As we can meet calcuim carbonate everywhere on earth. The chalk in the teacher’s hand, the stone in the wild and even the marble floor are all made of calcium carbonate. The chalk has been used for more than 10000 years although we are often worried about the teacher’s health, we still can’t find better solution for our dear teacher. And as the limestone,calcium carbonate is a kind of stone which is more compacted than chalk. The marble’s structure is different from the limestone’s because of this it is called coarse-crystalline. It is formed in special environment of high temperature and pressure. Large amouts of marble are found in North America. As a result a quite famous sculpture named Michelangelo appeared.