What is limestone?

Limestone is a Carbonate sedimentary rock. It is often composed of the skeletal fragments of marine organisms such as coral, foraminifera, and mollusks, shell, algal, and fecal debris. Some of these organisms can construct mounds of rock known as reefs, building upon past generations. Below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water. Its basic materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate.

Often 10% of sedimentary rocks are Limestones. The solubility of Limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the Limestone over thousands to millions of years. Most cave systems are through limestone bedrock.

How is limestone formed?

Limestone is a sedimentary rock so that it may be organic, chemical or detrital in origin.

In this part, we explain how Limestone is formed as organic.

The sediment that goes to make up Limestone may have been derived from the dead remains of marine organisms such as:

  • Shells
  • Microscopic algae
  • Bryozoa
  • Corals
  • Crinoids

Next, these organisms remove calcium carbonate (CaCO3) from the sea water to construct shells or skeletons.

Finally, CaCo3 cement, which may be fine grained or coarse grained, holds the fossils together to form a Limestone.

Limestone Properties

Limestone is a chemical sedimentary rock, which forms from the solidification of minerals out of solution into rock form. Because the chemicals in limestone can be readily dissolved by acidic solutions and water, they are able to form karst topography.

Karst topography forms when Limestone bedrock chemically reacts with liquids to form unusual features, like stalactites and stalagmites. When calcium-rich minerals in Limestone are dissolved into groundwater, it forms what is referred to as hard water or water that has higher than normal pH and mineral content.

Depending on the conditions under which they formed, Limestone can take on a number of structural shapes, including granular, massive, or clastic.

It is wonderful, when Limestones of any type undergo metamorphism, they re-crystallize as marble. Because all Limestone contains calcium carbonate, which reacts with hydrochloric acid to produce bubbles. Acid testing is best and reliable field tests for Limestone and calcite mineral identification.

Types of limestone

This section is a list of types of Limestone. You can see it with pictures.

  • Carboniferous Limestone
  • Bituminous Limestone
  • Fossiliferous Limestone
  • Lithographic Limestone
  • Shelly Limestone
  • Coquina
  • Coral rag
  • Chalk
  • Oolite
  • Rag-stone
  • Travertine
  • Tufa

Colors of Limestone

  • Silver Buff
  • Rustic Buff
  • Gray
  • Rustic Gray
  • Full Color Blend

Uses of Limestone

Limestone was a very favorite building block in the middle Ages in the areas where it occurred. Many medieval churches and castles in Europe are made of Limestone.

Some varieties of Limestone perform well in these uses. Because they are strong, dense rocks with few pore spaces. These properties enable them to stand up well to abrasion and freeze-thaw.

Important uses of Limestone include:

Dimension Stone: Limestone is very common in architecture. Often in Europe and America uses this stone. Because it is readily available and relatively easy to cut into blocks or more elaborate carving.

Roofing Granules: Crushed to a fine particle size, crushed Limestone is used as a weather and heat-resistant coating on asphalt-impregnated shingles and roofing. It is also used as a top coat on built-up roofs.

Flux Stone: Crushed Limestone is used in smelting and other metal refining processes. In the heat of smelting, Limestone combines with impurities and can be removed from the process as a slag.

Portland cement: Limestone is heated in a kiln with shale, sand, and other materials and ground to a powder that will harden after being mixed with water.

Mine Safety Dust: this uses is very important and useful. Pulverized Limestone is a white powder that can be sprayed onto exposed coal surfaces in an underground mine. This coating improves illumination and reduces the amount of coal dust that activity stirs up and releases into the air. This improves the air for breathing, and it also reduces the explosion hazard produced by suspended particles of flammable coal dust in the air.

Limestone finishes

Smooth: as a popular Limestone finish. The least textural of the standard finishes and presents minimum surface interruption. Terms associated with a smooth finish are often called out as honed, grinder, machine, bugged, planer or circular sanded.

Sandblasted: is commonly used to match newly installed Limestone materials with older Limestone encountered during a restoration project. The finish can be applied to newly installed material on commercial and residential projects as well.

Split Faced: This finish is rough that appearance creates maximum light and shadow contrast. It is used for residential and commercial buildings alike on both interior and exterior to emphasize horizontal lines and create a massive appearance.

Tumbled: The gentle tumbled stone treatment imparts a unique and individualized char acter upon every stone. This natural finish elevates and refines every project with its natural beauty and favorite for both residential and commercial customers.

Rock Face: it has been dressed by hand or machine to produce a bold, convex projection along the face of the stone. This finish provides a bolder, more massive appearance than split face.