Rocks

Limestone, a sedimentary rock, because the rock is hard, compact, fine grained by feel, and looks white, and somehow glittering. The rock also feels wet and cool.

Attributes of its formation

Sedimentary rocks are grouped into two depending on the textures. There is the clastic type, which forms from deposition of some solid grains. These rocks are by the lithification of weathered rock debris, transported and deposited elsewhere. In the course of this transportation process, abrasion takes place and the particles that make up these rocks become rounded. Thus, the rocks are classified according to the grain size. Examples of these rocks are the shale, sandstone, and conglomerate.

The second type is the chemically formed type, which forms from the precipitation and crystallization of minerals out of water or they can be because of lithification of once living organic matter, hence non-clastic. These types are classified according to the mineral content in the rock. Their formation mostly involves some sorts of chemical reactions. Examples of rocks are limestone, and bituminous coal.

Lithification refers to any process, which turns raw rock sediment into a consolidated sedimentary rock. Generally, all sedimentary rocks are lithified to form a collective mass. This lithification process is what produces visible layers in the sedimentary rocks. Lithification occurs by way of drying, oxidation of iron and aluminum, and precipitation of calcium and silica.

Formation

The oceans are saturated with calcium carbonate from the shells of marine organisms. Because these organisms are surrounded in a solution, some of their calcium carbonate, which is used for the construction of their shells and other parts of the body, dissolves into the sea. When subjected to the right conditions, this dissolved calcium carbonate precipitates out forming chemically created rock deposits called limestone. Limestone is mostly found on sea banks, lakes, and rivers. Countries with large deposits of limestone are Europe, on Oland island, and Gotland island in Sweden.