Ca2MgCO32

Ca2MgCO32 is a chemical compound, specifically a carbonate mineral. It is known by the mineral name dolomite. Dolomite is a double carbonate of calcium and magnesium with the chemical formula CaMg(CO3)2. In its pure form, it contains approximately 54.35% calcium oxide (CaO) and 45.65% magnesium oxide (MgO) by weight, although natural dolomite often contains minor substitutions of other elements.

Dolomite is a common rock-forming mineral. It is the primary constituent of the sedimentary rock dolomite, also known as dolostone. This rock is often formed by the diagenetic alteration of limestone, a process called dolomitization, where magnesium replaces some of the calcium in the original calcium carbonate (calcite) structure. Dolomite can also form through direct precipitation from seawater, though this is less common.

The mineral typically occurs as rhombohedral crystals. It is generally white, gray, or colorless, but can be tinged with other colors due to impurities. Dolomite is harder than calcite, but softer than quartz. It is insoluble in water but will react with dilute hydrochloric acid, although it fizzes more slowly and less vigorously than calcite, especially when cold. Dolomite has various industrial uses, including as a source of magnesium, in the production of refractory materials, as an aggregate in construction, and in the agricultural industry as a soil conditioner.