Minerals are natural formations that are extracted from the surface of the Earth or from the bowels of the earth, and then used for various purposes. One of the groups is construction fossils, such as limestone, sand, granite and clay. Granite is a complex mineral that has three minerals, namely mica, quartz, and feldspar. This material is used for facing metro stations and buildings. Limestone was formed from petrified shells of ancient marine mollusks. Slabs formed from limestone-shell rock have a beautiful patterned structure and are used for decoration. Sand and clay are used in the manufacture of bricks, cement, and concrete. You can read more about each fossil in the article.
Sand and its description
If you wondered what sand is, then you should read the information below. This is a sedimentary rock or artificial material that contains rock grains . Quite often, sand consists almost entirely of pure quartz. If we talk about the natural variety of sand, then it is characterized as a loose mixture of individual grains, the fractionality of which varies from 0.1 to 5 millimeters. Elements are formed during the destruction of hard rock. Depending on the genesis, natural sands can be lacustrine, marine, alluvial, deluvial, as well as aeolian. If you are faced with the question of what sand is, then you should know that it can arise during the activities of watercourses and reservoirs, in which case the elements have a more rounded and rounded shape.
Varieties of sand
Among the varieties can be distinguished river sand, which is extracted from the river bed. It is distinguished by an excellent degree of purification and the absence of clay impurities, foreign inclusions and small stones. The quarry variety is mined by washing with a large volume of water. As a result, dusty elements and clay are washed out of the composition. Most often in construction is used the same name sand, which is a loose inorganic material. Fractionality in this case does not exceed 5 millimeters. It is formed during the natural destruction of rock formations. If you are faced with the question of what sand is, then you should be interested in its radioactivity. According to GOST 30108-94, this substance can be used for all types of construction work without restriction, which indicates radiation safety.
What is clay?
If you decide to find out what sand and clay are, then the latter is a sedimentary fine-grained rock that can turn into a dry state, acquiring dustiness. When wetted, the substance becomes plastic. The composition may be one or more minerals of the kaolinite group. Among the ingredients can be all kinds of clay minerals, as well as carbonate and sand particles. As the forming mineral, kaolinite acts, as for silicon oxide, it is contained in a volume equal to 47%. Alumina is contained in a volume of 39%, while water in an amount of 14%. The main source of the described rocks is feldspar, which decomposes under the influence of atmospheric phenomena. Some clays that have sedimentary origin are formed during the accumulation of these minerals. However, most of them are sediments of water flows that fall to the bottom of the seas and lakes.
Granite and its description
What is sand, was described above, now you can learn about the features of granite. It is an igneous acidic intrusive rock, which consists of feldspar, mica, quartz, and also plagioclase. Granites are quite common in the continental crust. The density of this substance is 2600 kilograms per cubic meter, while the compressive strength reaches 300 MPa. Granite can be called one of the most important rocks of the earth's crust. It plays a significant role in its structure. Granite is formed to the greatest extent in the collision zones where continental plates collide and the continental crust thickens.
After reading this article, you can find out what sand, clay, granite, limestone is. The penultimate breed is one of the most dense substances, which is characterized by strength and hardness. It is used in construction as a facing material. Among other things, granite has little water absorption and excellent resistance to pollution and frost. That is why it is considered optimal for paving outdoors and indoors. However, it must be remembered that such a room will have a slightly more significant radiation background.
Limestone description
If you are interested in what building sand and limestone are, then both of these concepts will become known to you after reading this article. The latter substance is a sedimentary rock of chemogenic or organic origin. Mostly limestone consists of calcium carbonate, which is represented by calcite crystals of various sizes. Due to the presence of calcium carbonate, limestone is capable of partially slowly dissolving in water. It decomposes to carbon dioxide, as well as to the corresponding bases. It is formed with the participation of living organisms in marine basins. This breed is part of the mountain ranges, and is also quite common in other places. The material is gloss-free and has a light gray tint. However, it can be white or almost dark. Color depends on the composition of impurities.
Conclusion
If you wondered what sand is for children, then it can be purchased at building materials stores. During its manufacture, a certain amount of clay is added, which allows to achieve a plastic consistency suitable for the sandbox.