Gypsum is one of the most abundant minerals in the world. It is extracted from the bowels of the earth everywhere and is widely used in industry, the construction industry, and medicine. In our article you will find a detailed description and photo of the gypsum mineral. In addition, you will learn about the main areas of its application.
Mineral gypsum: description and chemical composition
The name of the mineral, rock, as well as the corresponding building material comes from the Greek word gipsos ("chalk"). Humanity has known about gypsum since ancient times. He has not lost his popularity these days.
Gypsum is a soft mineral. Incidentally, it is a reference for the Mohs scale of relative hardness, adopted at the beginning of the 19th century (hardness - 1.5-2.0).
According to the chemical composition, the gypsum mineral is an aqueous calcium sulfate. Its structure includes elements such as calcium (Ca), sulfur (S) and oxygen (O). We will describe the chemical composition of gypsum in more detail:
- Sulfur trioxide, SO 3 - 46%;
- calcium oxide, CaO - 33%;
- water, H 2 O - 21%.
Genetic classification: monoclinic syngony. This mineral is distinguished by a layered crystalline structure and very perfect cleavage (it is easy to split off individual thin "petals" from it).
Mineral gypsum: properties and distinguishing features
Here are the basic physical characteristics of gypsum, by which it can be distinguished from other minerals:
- fracture uneven but flexible;
- Shine: from glass to silky or matte;
- hardness: low (easily scratched with a fingernail);
- the mineral slowly dissolves in water;
- not greasy to the touch;
- leaves behind a clearly visible white line;
- color: white to gray (sometimes it can be pink).
Gypsum does not react with acids, but it dissolves in hydrogen chloride (HCl). It can have different transparency, although the transparent mineral gypsum is more common in nature. When heated above 107 degrees Celsius, gypsum turns into alabaster, which, in turn, hardens when wetted with water.
Gypsum is often confused with anhydrite. These two minerals can be distinguished from each other by hardness (the second is much harder than the first).
The genesis of the mineral and its distribution in nature
Gypsum is a typical mineral of sedimentary origin. Most often, it is formed from natural aqueous solutions (for example, at the bottom of drying seas and ponds). Mineral gypsum can also accumulate in the weathering zones of native sulfur and sulfides. In this case, the so-called gypsum hats are formed - loose or compacted rock masses contaminated with numerous impurities.
In sedimentary rocks, gypsum is often found accompanied by sand, rock salt, anhydrite, sulfur, limestone and iron. Neighborhood with the latter, as a rule, gives it a brownish tint.
In nature, gypsum is found in the form of elongated and prismatic crystals. It also often forms dense scaly, fibrous or “tablet” aggregations. Often, gypsum is presented in the form of so-called roses or dovetails.
The main types of mineral
Geologists distinguish several dozen varieties of gypsum. The mineral can be fibrous, satin, dense, foamy, fine-grained, bone, cubic, etc.
The main varieties of gypsum include:
- selenite;
- alabaster;
- Marino glass.
Selenite is a translucent mineral with a silky sheen. The name comes from the Greek word selena - "moon". This mineral really has a slightly bluish tint. Selenite is used as an ornamental stone in the manufacture of budget jewelry.
Alabaster is a soft, easily destructible material of white color, a product of gypsum dehydration. It is widely used in the manufacture of garden sculptures, vases, countertops, stucco moldings and other interior items.
“Maryino glass” (girl’s or ladies ’ice) is another type of gypsum, a transparent mineral with a mother-of-pearl or colored shimmer. It features a unique crystal lattice structure. In ancient times, “marino glass” was widely used in the design of icons and holy images.
Major gypsum deposits
The gypsum mineral is ubiquitous in the earth's crust. Its deposits are found in deposits of almost all periods of the geological history of the planet - from the Cambrian to the Quaternary. Deposits of gypsum (as well as its accompanying anhydrite) in sedimentary rocks are in the form of lenses or formations with a thickness of 20-30 meters.
Over 100 million tons of gypsum are extracted annually from the bowels of the earth. The largest world producers of valuable building materials are the USA, Iran, Canada, Turkey and Spain.
In Russia, the main deposits of this breed are concentrated on the western slopes of the Ural Mountains, in the Volga and Prikamye, Tatarstan and the Krasnodar Territory. The main gypsum deposits in the country: Pavlovsk, Novomoskovsk, Skuratovsk, Baskunchak, Lazinsk and Bolokhov.
Gypsum Applications
The scope of gypsum is extremely wide: construction, medicine, repair and decoration, agriculture, chemical industry.
From the most ancient times, sculptures and various interior items — vases, countertops, balustrades, bas-reliefs, etc., have been carved out of this mineral from this mineral. Cornices, wall blocks and slabs (the so-called drywall) are often made from it. In the "raw" form, gypsum is also used in agriculture as fertilizer. It is scattered in the fields and lands to normalize the acidity of the soil.
Where else is gypsum used? The mineral is widely used in the paper and chemical industries for cement, sulfuric acid, paints and glazes. In addition, anyone who has ever broken a leg or arm is familiar with yet another area of its application - medicine.
Gypsum as a building material
Building material gypsum is obtained from gypsum stone. To do this, the rock is fired in special furnaces, and then ground into a fine powder. In the future, the resulting raw materials are widely used in construction and decoration.
The industrial industry has its own classification of gypsum - technical. So, the following varieties of it are distinguished:
- high-strength gypsum (used in medicine and dentistry; it also produces various building mixtures and forms for the porcelain industry);
- polymer (used exclusively in traumatology for the application of fixative dressings for fractures);
- sculptural (the name speaks for itself - this is the main component of putty mixtures, various figurines and souvenirs);
- acrylic (lightweight gypsum used to decorate building facades);
- refractory (non-combustible material from which plasterboard sheets and wall blocks are often made).
In addition, there is a separate marking of gypsum for strength. According to her, 12 grades of gypsum stand out - from G2 to G25.
Alabaster is also widely used in construction and finishing works. Compared to gypsum, it is more durable and easy to process. True, without special additives, alabaster is practically unsuitable, since it dries instantly.
It is important to note that even with the modern, so high level of development of science and industry, no worthy replacement for gypsum has been found.
The healing and magical properties of stone
Plaster is not in vain used in medicine. It contributes to the fusion of bone tissue, eliminates excessive sweating, and cures spinal tuberculosis. Gypsum is also used in cosmetology - as one of the components of tonic masks.
From ancient times, this mineral was considered a kind of "cure" for human pride, arrogance and excessive arrogance. In magic, it is believed that gypsum is able to tell a person what he needs to do in a given situation. It promises good luck and material well-being. Astrologers advise wearing gypsum amulets to people born under the signs of Capricorn, Aries and Leo.
Desert Rose - what is it?
Such a beautiful name is called a mineral aggregate, one of the varieties of gypsum. It really resembles the appearance of flower buds. Aggregates consist of crystalline lenticular splice-petals of a characteristic type. The color of “desert roses” can be the most diverse. It is determined by the color of the soil or sand in which it is formed.
The mechanism of formation of these "roses" is quite interesting. They are formed in particularly arid climatic conditions. When rain occasionally falls in the desert, sand immediately absorbs moisture. Water interacts with particles of gypsum, which are washed with it deep into it. Later, water evaporates, and gypsum crystallizes in the sand mass, creating the most unexpected and bizarre forms.
The Desert Rose is well known to the nomadic tribes of African Sahara. Some cultures in the region have a tradition of giving these stone flowers to their lovers on Valentine's Day.