Dolomite is a common rock-forming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg(CO3)2. It is the primary component of the sedimentary rock known asdolostone and the metamorphic rock known as dolomitic marble. Limestone that contains some dolomite is known as dolomitic limestone. it is rarely found in modern sedimentary environments but dolostones are very common in the rock record. They can be geographically extensive and hundreds to thousands of feet thick. Most rocks that are rich in dolomite were originally deposited as calcium carbonate muds that were postdepositionally altered by magnesium-rich pore water to form dolomite Dolomite occurs in a solid solution series with ankerite (CaFe(CO3)2). When small amounts of iron are present the dolomite has a yellowish to brownish color. Dolomite and ankerite are isostructural.
<h2>Properties Of Dolomite</h2>
The mineral dolomite crystallizes in the trigonal-rhombohedral system. It forms white, gray to pink, crystals. Dolomite is a double carbonate, having a different structural arrangement, and it does not rapidly dissolve or effervesce (fizz) in dilute hydrochloric acid. Crystal twinning is common. A solid solution series exists between dolomite andiron rich ankerite. Small amounts of iron in the structure give the crystals a yellow to brown tint. Manganese substitutes in the structure also up to about three percent MnO. A high manganese content gives the crystals a rosy pink color noted in the image above. A series with the manganese rich kutnohorite may exist. Lead and zinc also substitute in the structure for magnesium. The mineral is closely related to huntiteMg3Ca(CO3)4. Because dolomite can be dissolved by slightly acidic water, areas of dolomite are important as aquifers and contribute to karst terrain formation.
Construction Industry
he Dolomite is a common rock-forming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg(CO3)2. It is the primary component of the sedimentary rock known asdolostone and the metamorphic rock known as dolomitic marble. Limestone that contains some dolomite is known as dolomitic limestone. Dolomite is rarely found in modern sedimentary environments but dolostones are very common in the rock record. They can be geographically extensive and hundreds to thousands of feet thick. Most rocks that are rich in dolomite were originally deposited as calcium carbonate muds that were postdepositionally altered by magnesium-rich pore water to form dolomite Dolomite occurs in a solid solution series with ankerite (CaFe(CO3)2). When small amounts of iron are present the dolomite has a yellowish to brownish color. Dolomite and ankerite are isostructural.
Acid Neutralization
Dolomite's reaction with acid also makes it useful. It is used for acid neutralization in the chemical industry, in stream restoration projects and as a soil conditioner.
Dolomite is used as a source of magnesia (MgO), a feed additive for livestock, a sintering agent and flux in metal processing and as an ingredient in the production of glass, bricks and ceramics.
It serves as the host rock for many lead, zinc and copper deposits. These deposits form when hot, acidic hydrothermal solutions move upward from depth through a fracture system that encounters a dolomitic rock unit. These solutions react with the dolomite which causes a drop in pH that triggers the precipitation of metals from solution.
It also serves as an oil and gas reservoir rock. During the conversion of calcite to a volume reduction occurs. This can produce pore spaces in the rock that can be filled with oil or natural gas that migrate in as they are released from other rock units. This makes the dolomite a reservoir rock and a target of oil and gas drilling.
