发表时间:2019-01-22
Calcite is a kind of calcium carbonate mineral, which is the most common natural calcium carbonate. Therefore, calcite is a widely distributed mineral. Calcite crystals are of various shapes. Their aggregates can be clusters of crystals or granular, massive, fibrous, bell-emulsion, Earth-like and so on. Knock on calcite to get a lot of square fragments, so the name of the solution. The color of calcite varies with the impurities in it, such as yellowish, reddish, brown and black when iron and manganese are contained. But they are usually white or colorless. Colorless and transparent calcite is also called Iceland stone. This kind of calcite has a wonderful feature, that is, it can see double images of objects through it. Therefore, Iceland stone is an important optical material. Calcite is the main mineral of limestone and marble. It has many uses in production and life. We know that limestone can form karst caves. The stalactites and stalagmites in the caves are actually composed of calcite. Calcite often contains isomorphic substitutes such as Mn, Fe, Zn, Mg, Pb, Sr, Ba, Co, TR, etc. When they reach a certain amount, they can form manganese calcite, iron calcite, zinc calcite, magnesia calcite and other varieties. In addition, brucite, dolomite, hydroxides of iron and mechanical mixtures of oxides, sulfides and quartz are also common in crystals. Trigonal system; common intact crystals. There are more than 600 kinds of polymers in various shapes. They are mainly parallel columnar, parallel plate and rhombohedral or compound trigonal partial triangular. Calcite often forms contact twins, and more often polycrystalline twins. The orientation of the polycrystalline twins on cleavage plane is different from that of dolomite. In nature, the appearance of polycrystalline twins can be used to explain that calcite was subjected to geological stress after its formation.