Biotite: what properties does it differ in and how can a stone be used?

Biotite is a mineral that is also known under the names of iron mica. It is a translucent plate or less transparent crystals. This mineral can be seen in various shades: bronze, yellow, dark green, reddish brown and black.

The study of this mineral began in the XIX century. Jean-Baptiste Biot, a military specialist, academic, physicist and mathematician, in whose honor the stone was named, was actively involved in its research and description. Mineralog Johann Housman continued the work begun by the French scientist and delimited a separate group of biotite substances. Only by the beginning of the XXI century could one call the knowledge about stone relatively complete.

Biotite is often found in nature, only in the earth's crust its presence is about 2-3%, which is a considerable indicator. Most often, the word biotite implies brown or black shiny mica, but also the concept biotite can replace the group of ferro dominant members of the phlogopite – annit series.

In nature, you can see very large stones, they are eager to get collectors. This is not surprising, because even among these seemingly inconspicuous stones, you can find large plates, which in their ability to reflect the image resemble a mirror.

Note that not so long ago there was an opinion that Biotite cannot be ranked as minerals. Scientists have decided that this is a solid solution of various natural substances. But for the time being we will focus on the traditional point of view, which implies the status of a mineral in biotite.

There are several types of mineral in origin, Depending on this parameter, biotites are divided into the following groups:

• granitewhich is contained in magma rocks;
• metamorphic - found in schists or gneisses;
• pegmatite - present in basalt sediments.

Mineral crystals have different colors, which are determined by rock impurities. There are black and brown specimens, sometimes in nature there are stones with a green or reddish tint. Mineral crystals are columnar or tabular in shape. Leaflets can be described as elastic, this mineral is more elastic than many others. Light can penetrate through biotite plates.

The fusibility of the stone varies for different types. For example, Miass biotite melts from 11.5 thousand degrees. The chemical composition of the stone is also different and can only be outlined within certain limits. As a rule, the structure of the stone implies the following components: potassium oxide takes from 4.5 to 8.5%, magnesium oxide from 0.3 to 28%, ferrous iron oxide - from 2.8 to 27.5%, aluminum oxide - from 9.5 to 31.5%, silicon oxide from 33 to 45%, water from 6 to 11.5%.

As impurities, oxides of lithium, sodium, barium, titanium, manganese, strontium, cesium, etc. are also found in biotite. They can give the stone a small radioactive background. To decompose the mineral you need to act on it with a concentrate of sulfuric acid.

As we have said, the coloring of the biotite stone varies depending on the impurities. We list the main types of biotite, depending on this parameter.

• Lepidomelans - have a rich black color.
• Meroxenes - due to the low concentration of iron impurities are transparent.
• Rubellans - they are distinguished by brown or terracotta shades.
• Siderofillity - they lack magnesium, but there are many impurities of iron. Therefore, the color of these unusual stones is greenish.

In the fields it finds biotite having various forms. It is found in the form of plate, scaly and columnar formations. Often this stone lies in the rocks adjacent to feldspars, granites, muscovites and andalusites. Biotite is so widespread that among the mica in quantity it is second only to muscovite. Therefore, it makes sense to mention only the most famous fields.

In the Ilmensky mountains a stone comes across as a minor mineral in pegmatite veins. There it lies in the form of plates up to half a meter in diameter or in crystalline form. In the Borschovochny ridge, biotite is observed on the Slyudyanka River. They find large biotite plates in Greenland, as well as in Scandinavia - on these lands there are even seven-meter plates, which is a large size. In Germany, this mineral is included in granites; biotite pegmatites are often found in the Granulitic mountains. Also known sources of the mineral are located in the areas of Burgmau and the Turegen Forest.

The stone is characterized by a glass shine its specific weight is 2.8-3.4 g / cm3. For some species characterized by the presence of features. Possesses perfect cleavage, can decompose into leaves. Interference coloring in red, blue, green tones. The hardness of the stone is not very high - it can not scratch the glass.

If erosion occurs, the biotite takes the form of a placer with all its signs, is easily separated with the thinnest silt material in stagnant waters. The mineral biotite vermiculite appears. After a certain time, the stones obtained receive a golden color due to the spangles, which, when washed, precipitate.

Lithotherapists note the ability of the mineral to heal nervous disorders, alleviate anxiety, stabilize the pulse and establish healthy sleep in people who suffer from insomnia. Biotite improves the protective functions of the body, and also stabilizes the endocrine system, contributes to the normalization of blood sugar. Among minerals experts, biotite is known as a stone with some magical properties. They can vary depending on the colors in which biotite is colored.

• To gain material well-being, in a purse you need to put the pieces of the mineral in bronze tones.
• In order for peace and tranquility to reign in the soul, experts advise carrying green copies with them.
• Pink-red stones guard the family hearth. They also help to find happiness in personal relationships.

Practical application of biotite includes various areas.

• Engineering. Since biotite, as well as all other mica, perfectly isolates, it is actively used in electronics, namely when creating instruments necessary in shipbuilding and aircraft industry. The plates have been used in the development of navigation devices. For the production of small technology mineral is also widely used, for example, with the production of microwave ovens.
• Building. Biotite is part of vermiculite, so it is used as a filler in the creation of sound insulation and heat insulation in homes. Its decorative properties are also valued - it can be used when facing panels of wood, giving them a more beautiful and expensive look. Also, mineral powder is sometimes added to the tile.
• Gardening. Due to the good ion exchange of the stone, it is saturated with liquid fertilizers with trace elements useful for plants.
• Repairs. In the production of various paints and enamels biotite is added to obtain heat-resistant coating compositions.
• Cosmetic industry. From a stone receive fine nacreous particles which are added to powders and other decorative cosmetics.
• In jewelry. Using the cabochon method, craftsmen get stones that adorn various jewelry items: rings, earrings, pendants, pendants, etc. A biotite placer in the composition of the feldspar gives a stone, called aventurine. An interesting fact is that the rarest effect for emeralds - a six-pointed star is obtained if particles of biotite fall into a crystal.
• In geology. Scientists use the isotopic geochronological method to determine the age of mountain fragments using biotite.
• Decor. Mineral can be used to create glitter for toys and theatrical scenery.

Despite the fact that the field of application of the mineral is already quite wide, it is still being closely studied and new promising areas are being found. So, biotite is a very common mineral found in different parts of the planet. It serves as a material for the creation of technology, including large units in mechanical engineering, in construction, in the cosmetic industry and other areas.

In the next video you can take a look at biotite in motion.