Carbonate rock: description, features, composition and classification

On Earth, there is a huge number of different rocks. Some of them have similar features, therefore they are united in large groups. For example, one of them is carbonate rocks. About their examples and classifications read in the article.

Classification by origin

Carbonate rocks were formed in different ways. In total, there are four ways of forming this type of rock.

• From chemical sediments. Thus there were dolomites and marls, limestones and siderite.
• Of the organogenic sediments formed such rocks as algal and coral limestones.
• Sandstone and conglomerates formed from the debris .
• Recrystallized rocks are some types of dolomite and marble.

Structure of carbonate rocks

One of the most important parameters by which the rocks necessary for production and processing are selected is their structure. The most important aspect of the structure of carbonate rocks is their granularity. This parameter divides the rocks into several types:

• Coarse-grained.
• Coarse-grained.
• Medium-grained.
• Fine-grained.
• Fine-grained.

Properties

Due to the fact that there are a large number of rocks of carbonate type, each of them has its own properties, for which it is very valued in production and industry. What physical and chemical properties of carbonate rocks are known to people?

• Good solubility in acids. Limestones dissolve in the cold state, and magnesite and siderite - only when heated. However, the result is similar.
• High frost resistance and good refractoriness are undoubtedly the most important qualities of many carbonate rocks.

Limestone rocks

Any carbonate rock consists of minerals of calcite, magnesite, siderite, dolomite, and also various impurities. Because of the differences in composition, this large group of rocks is divided into three smaller ones. One of them is limestone.

Their main component is calcite, and depending on the impurities they are divided into sandy, clayey, siliceous and others. They have different textures. The fact is that on the cracks of their layers, one can discern traces of ripples and rain drops, salt crystals, which are soluble, as well as microscopic cracks. Limestones can be different in color. The dominant color is beige, grayish or yellowish, and the impurities have a pink, greenish or brownish tinge.

The most common limestone rocks are the following:

• Chalk is a very soft rock, which is easily triturated. It can be broken by hand or pounded into powder. It is considered a type of cemented limestone. Chalk is an invaluable raw material used in the production of cement building material.
• Lime tuffs are porous loose rock. It is sufficiently easy to develop. Shells are almost as important.

Dolomite rocks

Dolomite - a rock, the content of the mineral dolomite in which is more than 50%. Often they contain impurities of calcite. Because of this, you can observe some similarities and differences between the two groups of rocks: dolomites and limestone proper.

The dolomites differ from limestone in that they have a more pronounced luster. They are less soluble in acids. Even the remnants of organic matter are much less common in them. The dolomite color is represented by greenish, pinkish, brownish and yellowish tints.

Which dolomite rocks are most common? It, first of all, will throw - more dense stone. In addition, there is graderite of soft pink color, it is widely used in interior design. Teruelite is also a kind of dolomite. This stone is remarkable in that it is found in nature only in black, while the other rocks of this group are painted in light shades.

Carbonate-clay rocks, or marls

The composition of carbonate rocks of this type includes a lot of clay, namely - almost 20 percent. In itself, a breed with this name has a mixed composition. Aluminosilicates (clay products of feldspar decomposition), as well as calcium carbonate in any form, are necessarily present in its structure. Carbonate-clay rocks are a transition link between limestones and clay. Mergels can have a different structure, dense or solid, earthy or friable. Most often they lie in the form of several layers, each of which is characterized by a certain composition.

High-quality carbonate rock of this type is used in crushed stone production. Mergel, containing impurities of gypsum, is of no value, therefore, this variety of it is almost not mined. If we compare this species of rocks with others, then most of all it looks like shales and siltstone.

Limestone

Any classification of carbonate rocks contains a group called "limestone." The stone, which gave it the name, was widely used in various industries. Limestone is the most popular breed in its group. It has a number of positive qualities, thanks to which and has become widespread.

There is limestone of different colors. It all depends on how much iron oxides are contained in the rock, because these compounds color limestone in many tones. Most often these are brown, yellow and red shades. Limestone - a fairly dense stone, it lies under the ground in the form of huge layers. Sometimes whole mountains are formed, the basic component of which is this rock. You can see the layers described above near the rivers with steep banks. Here they are very well seen.

Limestone has a number of properties that distinguish it from other rocks. To distinguish them is very easy. The easiest way to do it at home is to drop a little vinegar on it, just a few drops. After that, you will hear the hissing sound and the gas will begin to discharge. Other rocks have no such reaction to acetic acid.

Using

Each carbonate rock has found application in any field of industry. So, limestones along with dolomites and magnesites are used in metallurgy as fluxes. These are substances that are used in the smelting of metals from ore. With their help, the melting point of the ores decreases, which helps to separate metals from empty rocks more easily.

Such a carbonate rock, like chalk, is familiar to all teachers and schoolchildren, because with its help they write on the blackboard. In addition, chalk whitewashed walls. It also produces a powder for cleaning teeth, but at present this paste substitute is difficult to obtain.

Limestone is used to produce soda, nitrogenous fertilizers, as well as calcium carbide. Carbonate rock of any of the types presented, for example, limestone, is used in the construction of residential, industrial premises, as well as roads. It was widely used as facing material and aggregate concrete. It is also used for obtaining feed additives with minerals and for soil saturation with limestone. From it create building stones, for example, rubble and but. In addition, cement and lime are produced from this rock, which are widely used in many industries, for example, in metallurgical and chemical industries.

Collectors

There is a variety of rocks, such as collectors. They have the ability to allow them to hold water, gas, oil, and for a while to give them back when developing. Why is this happening? The fact is that a number of rocks have a porous structure and this quality is very much appreciated. It is thanks to porosity that they can contain a large amount of oil and gas.

Carbonate rocks are collectors of high quality. The best in their group are dolomites, limestones, and also chalk. 42 percent of the oil collectors used and 23 percent of the gas collectors are carbonate. These rocks occupy the second place after terrigenous.