Many centuries rock remained the main construction material. People chose its types depending on features, durabilities, physical properties, wearability. As processing of a stone was business hard, objects from it built only the most important. The legendary pyramids and other constructions recognized as wonders of the world are built from such material.
Various stones not so chaotic heaps, but natural regularity. The unit of mineral of natural origin the structure and the building having constants is called breed. The first in geology the term was entered by the scientist Severgin in 1789.
Classification
Minerals are obliged by scopes of application to many characteristics. Mainly breeds apply to construction works. By education types all minerals divide into several categories:
- magmatic;
- sedimentary;
The mantle type stands alone.
The most part of bark of the earth consists of all versions. Centuries emissions of volcanoes slezhivatsya. Magma, cooling down, hardened. Magmatic breeds were formed. They lie at various depths.
The sedimentary type is formed by fragments of various origin. Scientists determine all features of group by method of carrying out special researches.
Metamorphic types are obliged by emergence to transformations of sedimentary and magmatic minerals in terrestrial thickness. At these stones the unique structure, but it forms the basis that material of which the breed was formed. All processes of transformation happen directly in bowels of the earth.
Mantle versions had origin magmatic. However significant changes in a cloak caused transformations.
Characteristic of versions
From magmatic subspecies allocate two subclasses, effusive and intrusive minerals. Distinguish them on the nature of the movement to the place of hardening of magma. Refer hypabyssal and vein breeds to intermediate options. They are formed in stone cracks during a magmozastyvaniye.
Magmatic
Plutonic or intrusive minerals are formed during the millennia. Such formations may contain the huge sizes crystals as at big depths the cooling of magma takes place extremely slowly.
Though such minerals in the subsoil lie, at a raising and aeration quite often they are transformed to massifs of mountains. An example of such transformation – Shpitskorre in Namibia. Carry granite, syenite, labradorite and a gabbro to the main representatives.
Volcanic versions are formed at volcanic eruptions when magma escapes on a surface. They have no large crystals as cooling of time occupies a little. An example of similar formations – basalts and rhyolites.
Before them used for production of sculptures.
Sedimentary
Call organogenic, chemical or sedimentary rocks the main types. Distinguish them on ways of origin.
At superficial education, detrital minerals are formed by cementation and caking of separate pieces of breeds. Such formations are sandstones and conglomerates. In the Barcelonian Monserrat array the last option is considered. Education is created from the cobble-stones fastened with cement mortar.
Chemical are created from the particles of minerals which dropped out in water a deposit. Classify such formations by mineral structure. The most widespread call limestone. The Australian desert of the Pinnacle is formed by this breed.
The organogenic type is in many respects similar to coal. The subclass by caking of the remains of vegetable and animal origin is formed. All sedimentary formations are similar ability to be dissolved in water, porosity and existence of cracks.
Metamorphic
Usually division into classes is rather conditional. So, metamorphic both sedimentary, and magmatic minerals can be called. Their transformation took place with various degree of intensity.
It is easy to define initial breed if speed was small. High makes such research impossible. At minerals both the texture, and structure change. On this sign the metamorphic subspecies subdivide into slate and not slate.
Under the terms of education allocate regional, hydrothermal and contact groups. Carry gneisses to the first type. These huge boulders were exposed to external influences, for example, temperature, to pressure.
By means of thermosources there is a formation of hydrothermal minerals. At engagement with the boiled water enriched with ions the chemical reaction begins. As a result the pedigree structure changes. Are an example of similar transformation quartzite and dzhespilit. Quite often they are formed by limestones.
In case of a contact way magmatic intrusive masses affects minerals with temperature increase and chemically.
Properties
For the choice of scope of application properties of material have huge value. When using for facing the paramount value has appeal esthetic. If the decorative effect is especially important, then attention is paid to selection of color, the drawing of a stone.
Density, durability and porosity
Weight depends directly on density. Distinguish versions on ease and weight. At selection of stones for construction the weight of a design is defined by the bigger density of weight of breed. Parameter depends on porosity and structure.
One of the major properties is durability. It defines resistance of material to wear. The mineral is stronger, the longer keeps original state. By criterion allocate durability low, average and high.
The choice depends on structure, hardness. High-strength call a gabbro, quartzites, granites. Carry marble, travertine, limestone to averages. The lowest durability at friable limestones from tufa.
All versions have various porosity. It defines ability of a stone to moisture absorption, resistance to acids and salts. Special attention characteristic deserves when choosing mineral for facing. The criterion affects durability, durability, workability.
The porosity is higher, the less stone weighs, the it is simpler to process it. However at the same time fortress decreases, the material poliruyemost worsens.
Resistance to influences of moisture, salts and acids
Extent of moisture absorption is very important. From this criterion of envy resistance of mineral to a frost, influences of salts and acids. Because of the water which got to a time of a stone pressure when freezing amplifies, moisture volume increases.
The same processes cause also salts. At low porosity cracks are formed. The risk of splitting is sometimes high. In porous breeds pressure is distributed evenly. Cracks in similar materials do not appear.
Change is influenced by acid resistance. These substances are capable to destroy materials. So, dolomite, travertine and marble strongly suffer from influences of hydrochloric acid. But at limestone and granite almost zero susceptibility to it. Therefore many similar minerals structures of a cult successfully remained.
Education process
At first sight it seems that the huge massif did not change in anything in centuries. However external factors influenced and them. Thanks to classification it is possible to define what time of education the original form and what influence for them are capable to keep more perniciously.
For a long time the structure of breed changes. Transformations have character anthropogenic and natural. By means of melt water, wind, the sun, temperature differences destruction goes slowly, but is inevitable. Wind and a rain the form and structure change.
Human activity provokes anthropogenic changes. The equipment has a significant impact on destruction. The damaged breeds form cracks. Because of it collapses, destructions are possible. Thanks to the person the shape of minerals changes much quicker, than with the participation of the nature. Therefore eventually any hilly terrain changes original form.
In no small measure transformations depend on climate. Geological processes form a certain cycle of mineralogenesis. It begins with magma pouring out. Cooling down, it stiffens. Rock is formed. Its types are transformed, getting on a surface.
Temperature differences, water and wind promote formation of sedimentary type. Aeration, crushing, shifts – fragments slezhivatsya, turning into sedimentary. Eventually mountains plunge on depth.
Action of tectonic processes begins. There are metamorphic rocks. They melt, becoming magma. Stiffening, it turns into magmatic breed. The cycle begins anew. The petrology and petrography are engaged in studying history of origin of minerals.
Main types
Practical application was found for the majority of rocks. The most demanded is granite. The stones consisting of feldspar, mica and quartz happen several shades. Carry to the most rare burgundy, light gray and bluish-green.
Granite is perfectly polished, some versions successfully maintain heat treatment. Properties of a stone are highly appreciated very much. Therefore mineral is actively used for facing of facades, creation of sculptures.
Soft sandstones are also very demanded. Their types depend on a way of education. Sedimentary rocks are formed by sand cementation. Fine-grained minerals of the most various colors meet. Generally they are applied to facing.
By impact on dolomite with limestone of high temperatures with pressure marble is formed. It has excellent decorative opportunities, it is perfectly processed:
- Clearness and background are minimized by grinding.
- The drawing strengthens polishing.
- The skalyvaniye will clarify a background.
Distinguish a color, white or gray stone.
At strong consolidation of clay and its recrystallization under the strongest pressure slate is formed. Mineral has ability of splitting on thin plates. Copies vary on a coloring.
The black and light-painted samples meet. Dense material is durable is decorative. No processing is required to it. Use slate for facing outside and from within.
More others malachite, onyx, a jasper, opal, lazurite are appreciated. Semiprecious stones in the nature meet seldom. Use them for production of a jewelry, small interior objects.