Calcite is a calcium carbonate mineral, the most common of which is natural calcium carbonate. Therefore, calcite is a widely distributed mineral. Calcite has various crystal shapes. The aggregate of Haicheng talc can be clusters of crystals, it can be granular, massive, fibrous, stalactite, earthy, so on. Hitting calcite can get a lot of square fragments, so it is called square solution. The color of calcite varies depending on the impurities contained in it, such as light yellow, light red, brown black, etc. when containing iron manganese. But it is mostly white colorless. Colorless transparent calcite is also called ice continent. A wonderful feature of this type of calcite is that it can see the object as a double image. Therefore, glacial stone is an important optical material. Calcite is the main mineral of limestone marble, has many uses in production life. We know that limestone can form karst caves. Stalactites stalagmites white marble in the caves are actually composed of calcite. Calcite often contains isomorphic substitutes such as Mn, Fe, Zn, Mg, Pb, Sr, Ba, Co, TR; when they reach a certain amount, it can form manganese calcite, iron calcite, zinc calcite, magnesium calcite, etc. variant. In addition, crystals such as brucite, dolomite, iron hydroxides oxides, sulfides, quartz other mechanical inclusions are common. Trigonal system; intact crystals are common. There are various forms, with more than 600 kinds of different shapes. Mainly in parallel development of columnar parallel development of plate-like various states of rhombohedron complex trigonal trihedral. Calcite often forms contact twin crystals, more often forms polycrystalline twin crystals. The orientation of this polycrystalline twin grain on the cleavage plane is different that of dolomite. In nature, the appearance of such polycrystalline twin crystals can be used to It shows that after the formation of calcite, it has suffered the effect of geological stress.