The main component of calcite is calcium carbonate (CaCO3).

Calcite crystals are in the hexagonal crystal system, and the common crystalline form is hexagonal columns or hexagonal plates. Its color is usually colorless or white, but it can also appear in different colors such as gray, yellow, and brown. Calcite has a low hardness of about 3.5 and can produce visible scratches by scraping with a fingernail.

Calcite is one of the most common minerals in the earth's crust and is widely found in rocks, sediments and mineral deposits. It plays an important role in geological and biological action.

In terms of geological roles, calcite can be formed in different tectonic environments, such as stomatal fillings, veins and vein minerals in volcanic rocks. It is also one of the main components of important rocks such as limestone and marble. When limestone is subjected to geological conditions such as high temperature and pressure, calcite undergoes a metamorphic reaction and transforms into marble.

In terms of biological effects, calcite is one of the important components in organisms such as corals, shells, and marine algae. When these organisms die, their remains accumulate to form sediments that, over time, are compacted and chemically modified to eventually form calcite rocks. This is the process that led to the formation of some large-scale calcite sedimentary rocks, such as the Cretaceous dolomites.

Calcite also has some special physical and chemical properties. In optics, it has a birefringent property that allows it to split incident light into two directions of propagation and produce an interference phenomenon. This makes calcite an important material for observation and research under the microscope.

Precautions when using calcite

1. Prevent inhalation: calcite dust has an irritating effect on the respiratory system, and prolonged inhalation may lead to respiratory discomfort and respiratory difficulties. When using or handling calcite powder, wear suitable protective masks or masks to ensure good air circulation.

2. Avoid contact with skin: calcite is irritating to the skin, and excessive contact may cause discomfort such as dry skin, itching or rashes. When operating calcite, wear protective gloves and avoid direct contact with the skin.

3, pay attention to eye protection: calcite dust into the eyes will cause irritation and discomfort, and may even cause eye damage. When handling calcite, wear safety goggles or face shield to protect your eyes.