Calcite is a rock-forming mineral with a chemical formula of CaCO3. It is extremely common and found throughout the world in sedimentary, metamorphic and igneous rocks. Some geologists consider it to be a ubiquitous mineral, one that is found everywhere.
Calcite is the principal constituent of limestone and marble. These rocks are extremely common and make up a significant portion of Earth's crust. They serve as one of the largest carbon repositories on our planet.
The properties of calcite make it one of the most widely used minerals. It is used as a construction material, abrasive, agricultural soil treatment, construction aggregate, pigment, pharmaceutical and more. It has more uses than almost any other mineral.
Construction
The construction industry is the primary consumer of calcite in the form of limestone and marble. These rocks have been used as dimension stones and in mortar for thousands of years. Limestone blocks were the primary construction material used in many of the pyramids of Egypt and Latin America.
Modern construction uses calcite in the form of limestone and marble to produce cement and concrete. These materials are easily mixed, transported and placed in the form of a slurry that will harden into a durable construction material. Concrete is used to make buildings, highways, bridges, walls and many other structures.
Acid Neutralization
Calcite is used as an acid neutralizer in the chemical industry. In areas were streams are plagued with acid mine drainage, crushed limestone is dispensed into the streams to neutralize their waters.
Calcium carbonate derived from high purity limestones or marbles is used in medicine. Mixed with sugar and flavoring, calcium carbonate is made into chewable tablets used in the neutralization of stomach acids. It is also an ingredient in numerous medications used to treat digestive and other ailments.
Many Other Uses
In a powdered form, calcite often has an extremely white color. Powdered calcite is often used as a white pigment or whiting. Some of the earliest paints were made with calcite. It is a primary ingredient in whitewash and it is used as an inert coloring ingredient of paint.
