In everyday life and technology referred to as non-metallic rock solid natural and artificial origin. In geology, the word used stones of the concept rock mineral. The study and description of rocks, rocks and minerals, has been one of the sections of Geology - petrography.

In everyday life and technology referred to as non-metallic rock solid natural and artificial origin

We will begin the study of the Earth's mineral life to the study of inaccessible depths - with magma zone, where the temperature is slightly above 15000 C and a pressure which reaches tens of thousands of atmospheres.

Magma - a complex mutual solution melt huge amounts of substances. While it is boiling, soaked with water vapor and volatile gas, it goes its own internal work, and individual chemical elements combine to ready (but still liquid) minerals. But the temperature drops - influenced by whether the total cooling, either because the magma becomes colder and higher areas, but it begins to freeze and release themselves from the individual substances. Some compounds used in a solid state, than the others, they are crystallized and fell to the bottom of the still liquid mass. It emerged solids gradually crystallizing forces attracted more and more; The solid collected together, separating the liquid from the magma.

The magma moves to a mixture of crystals - in the mineral mass, which is called a crystal rock.

Hard rock - this is not the fact that the composition of the molten fire. A great number of volatile compounds impregnates his molten mixture, released powerful jets; and long smokes, her focus until the mixture hardens and forms a solid rock. Only a tiny part of the gas remains inside the solidified mass, the other part rises to the surface in the form of gas jets.

Not all of these volatile compounds have time to reach the earth's surface. A large part of them is deposited even in the depths, water vapor is condensed; through cracks and veins are flowing to the surface of the Earth's hot springs, cooled slowly and gradually separated from the solution of a mineral mineral.

The rock, which lies on the surface of the Earth, is composed of mineral aggregates for the most part small - or cryptocrystalline. Relatively rare rock found in the form of large, well-formed crystals. The rock - not always firm. There are soft rock, such as talc slate, gypsum rock, plastic rocks, easy to change shape, such as clay and loose - gravel, sand.

The names of the rocks were formed gradually, their origin is difficult. Most of them are associated with the words of two ancient languages - Latin and Greek. Names of rocks usually ends in "um": granite, porphyry, andesite, diorite, etc. This ending is part of the Latin word "lithos" stone, and says that so designated rock...

The rock is named on the basis of which at one time regarded as typical. For example, in the name of "granite" he emphasized grit stone, "marble" - shine crystals on fracture surfaces.

Hundreds of different titles gives us the science of petrography, trying to structure and chemical composition of stones and rocks to find the imprint of their past into the unknown depths of the Earth.