/ mineral Feldspar

Feldspars are a large group of widespread, in particular rock-forming minerals from the silicate class. Most feldspars are representatives of solid solutions of the ternary system of the isomorphic series K[AlSi3O8] - Na[AlSi3O8] - Ca[AlSi2O8], the end members of which are, respectively, orthoclase (Or), albite (Ab), anorthite (An).

There are two isomorphic series: albite (Ab) - orthoclase (Or) and albite (Ab) - anorthite (An).

Minerals of the first of them can contain no more than 10% An, and the second - no more than 10% Or. Only in sodium feldspars close to Ab does the solubility of Or and An increase. Members of the first row are called alkaline (K-Na feldspars), the second - plagioclases (Ca-Na feldspars). The continuity of the Ab-Or series appears only when high temperatures, at low temperatures, miscibility breaks with the formation of perthites. Along with sanidine, which is high-temperature, low-temperature potassium feldspars are distinguished - microcline and orthoclase.

Feldspars - most common rock-forming minerals, they make up about 50% of the mass of the Earth's crust.

General properties

Feldspars are silicates with a frame-type crystalline structure; these are openwork structures of silicon-oxygen tetrahedra, in which silicon is sometimes replaced by aluminum. They form rather uniform crystals of monoclinic or triclinic systems, in the form of a few combinations of orthorhombic prisms and pinacoids. Simple or especially polysynthetic twins are characteristic; The laws of twinning found in feldspars are divided into normal (perpendicular), for which the twinning axis is perpendicular to any possible face of the crystal located parallel to the plane of twinning, parallel, giving which the twinning axis is the edge of the crystal, and the plane of twinning is parallel to the twinning axis, and also more complex (combined) laws. In this case, the most frequently encountered are the albite (in plagioclase) and Carlsbad (in potassium field pshat) twinning laws.

All feldspars are easily etched by HF, and plagioclases are also destroyed by HCl.

Subgroups

Plagioclases
Plagioclases have the general formula (Ca, Na)(Al, Si) AlSi2O6:
Albite. (the extreme member of the isomorphic series, with the formula: NaAlSi2O6, contains 0-10% An.)
Oligoclase.
Andesine.
Labrador.
Bitovnit.
Anorthitis. (extreme member of the isomorphic series, with the formula: CaAlSi2O6, contains 90-100% An)

Origin

Plagioclases, mostly salic, are the main rock-forming minerals of igneous and many metamorphic rocks. In igneous rocks, plagioclase, rich in the An-molecule, first crystallizes, and then more acidic (rich in silica) is released. In these cases, zoned crystals may develop. Some igneous rocks consist almost entirely of plagioclases (anorthosites, plagioclasites, and others). Pegmatite veins often contain albite, formed from other plagioclases, and especially from sodium-containing potassium feldspars. Under hydrothermal conditions, plagioclases are altered by weathering into kaolinite minerals and sericite mica. At the same time, plagioclases rich in anorthite component are destroyed faster than acidic ones; albite is more stable during secondary processes.

Potassium feldspars

Potassium feldspars are often collectively simply referred to as "KPS":

  • Orthoclase (KAlSi3O8)
  • Sanidine (KAlSi3O8)
  • Microcline (KAlSi3O8)

All three minerals correspond to the same chemical formula, differing from each other only in the degree of ordering of their crystal lattices.

Structural features and nomenclature

Approximate scheme of isomorphism in alkali feldspars

The microcline is of triclinic system (pseudomonoclinic), the angle between the cleavage planes differs from the straight line by 20°. Sanidine is monoclinic, with a completely disordered structure (K(AlSi)4O8), stable at temperatures above 500 ° C, and orthoclase, also strictly monoclinic, has a partially ordered structure K(A1,Si)Si2O8 and is stable at temperatures between 500 ° and 300 °C. Below this temperature, the stable form is microcline. Orthoclases almost always contain some amount of Na2O; intermediate members between orthoclase and albite are called anorthoclases. The orthoclase-albite series is usually stable at high temperatures; lowering the temperature leads to the precipitation of albite in orthoclase (perthite) or orthoclase in albite (antiperthite). The solid solution with sanidine is a monoclinic modification of Na[AlSi308] containing some potassium and is known as barbierite; another modification of the same composition, but triclinic, forms a solid solution with high-temperature albite. Varieties: adularia (named after an area in the Alps), low-temperature orthoclase with or without weakly developed facets (010), sometimes iridescent and used as semiprecious stone(moonstone). Amazonite is a light green microcline. The crystallographic forms of pseudomonoclinic triclinic representatives are similar to those of orthoclase. Orthoclase is characterized by a right angle between the cleavage planes.

A staining method is used to distinguish plagioclases from potassium feldspars. To do this, the rock surface or mineral plate is etched with HF and then placed in a K-rhodizonate solution; — plagioclases, with the exception of albite, are painted brick-red.

Origin

Potassium feldspars are the main rock-forming minerals of acidic igneous rocks (granites, syenites, granodiorites, etc.), as well as some widespread metamorphic rocks (gneisses). The latter are dominated by low-temperature microcline, while igneous rocks of the plutonic type contain orthoclase, and volcanic rocks contain sanidine. Anorthoclase is a typical mineral of sodium-rich igneous rocks.

Orthoclase and microcline, together with quartz and muscovite, are the main minerals of pegmatites. If beryl is present in them, the microcline can be enriched in beryllium, which, like aluminum, can replace silicon atoms. Pegmatites are characterized by intergrowths of orthoclase (microcline) with quartz, known as “written granite” pegmatite and which are a product of crystallization of eutectic magmatic melt. Adularia is a typical feldspar in alpine-type hydrothermal veins.

Compared to plagioclases, K-feldspars are more resistant to destruction, but they can be replaced by albite, giving rise to “metasomatic perthite”. Under hydrothermal conditions and weathering, they change into minerals of the kaolinite group.

Deposits

Deposits of potassium feldspars are well known in Norway, Sweden, Madagascar, on the territory of the Ilmensky Nature Reserve and in many other pegmatite occurrences of the Southern Urals. Also in Maine, USA, and elsewhere.
Potassium-barium feldspars (Hyalophanes)
Potassium-barium feldspars (hyalophanes) are rare in nature. They are isomorphic mixtures of K[AlSi3O8] - Ba[Al2Si2O8].
Celsian (BaAl2Si2O8).
Hyalophane (K,Ba)(Al,Si)4O8
Quite a rare mineral. Individual cream-colored crystals have exclusively collection value.

Application

Feldspars are widely used in the ceramics industry as fillers, light abrasives (for example, in the production of toothpastes), and also as raw materials for the extraction of rubidium and some other impurity elements they contain. Due to its wide range of colors, feldspars are often used to make decorative decorations for home interiors, paintings and mosaics.

Some varieties of translucent and transparent plagioclases, which have an opalescent effect or silvery-bluish and golden iridescence, are used as ornamental stones in jewelry(moonstone, belomorite, labradorite).

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Properties of the Mineral

Color colorless, white, gray, bluish, yellowish, pink, brownish, in principle, due to inclusions, can have any color
Stroke color white
Origin of the name from him. "feld" - field and Greek. “spate” - a plate, due to the ability to split into plates along the cleavage
Opening year known since ancient times
Shine glass
pearl
Classes on taxonomy of the USSR Silicates
IMA classes Silicates
Fragility Yes
Literature Alekseev V.I., Sokolova N.G. Evolution of order and composition of alkali feldspars of the Northern granite massif (Chukotka). - Zap. RMO, 2007, part 136, issue 2, p. 62-74
Dolzhanskaya T.Yu. Use of typomorphic features of feldspars to identify the internal structure of the alkaline massif of the Cherry Mountains in the Urals. - App. and ecology aspects of minerals: abstract. report Godich. ses. All mineral. islands, Zvenigorod, March 19 – 21, 1990. Book 2. – M., 1991. – P. 61 – 63. Rus.
Kupletsky V.I. Feldspars in the Kem region. - KEPS materials. L., 1924. Issue. 48. Stone building materials. pp. 29-46.
Kurbatov S.S. Feldspars of the USSR and the possibility of using them in the ceramic industry. - Tr. State research ceramic in-ta. 1928. Issue. 2. P. 40.

Minerals Catalog

Feldspar stone is one of the most common minerals on the planet. Many gems are a variety of spar. They are beautiful and are not inferior in uniqueness to expensive precious formations.

History of the discovery of feldspar

The history of the stone does not have an exact date for the beginning of the discovery and use of the field mineral by people. A description of the mineral can be found in ancient sources different eras. The name of mineralogy was given by a literal translation from German language: A field mineral that fractures into individual lamellar layers. But the term itself is not a discovery of the Germans. It was formed from the name of agricultural land in Sweden. They were strewn with pieces of spar. Therefore, the opinion of geologists who classify the mineral as a Swedish-German term is considered correct. Cleavage should initially sound like spatality, that is, strong cohesion, the strength of the fusion of plates. There is information about the discovery of the first spar jewelry. These are excavations on the territory of the ancient states of the East and Egypt.

Physical and chemical properties

The physical properties of any mineral group are the same, but the chemical content is different. The stone looks like a plate of heterogeneous composition fused into a single whole. Formed in the form of twin crystalline compounds.

Properties and features of feldspar stone:

  • full degree of cleavage (perfect);
  • the shine of glass and mother-of-pearl surfaces;
  • the effect of the physical process of iridescence;
  • The hardness of crystals and adhesions is average.

The composition of spar has been studied by mineralogists, all representatives are divided into classification subgroups:

  • potassium Kalium;
  • sodium Na - calcium Ca;
  • potassium K – barium Ba.

The origin of the mineral is similar to granite. It owes its creation to magma and acidic environmental structure.

  1. The first type (potassium field minerals) is formed under hydrothermal conditions during the weathering of kaolinite. Stones of the group: microlins, sanidines, adularia.
  2. A subgroup of sodium-calcium stones has the effect of twin rocks with a triclinic structure. Their common name is plagioclase. Representatives of the subgroup: albite, andesine, labradorite, oligoclase, bytownite, anorthite. The rarest and most valuable is solar albite.
  3. The third subgroup of potassium-barium field minerals is the most valuable. It is found rarely, often as inclusions in another gem. The rocks are cream colored. One of the minerals of the species is celsian. This is a desirable find for collectors and lovers of special valuable pieces.

Deposits

The rock-forming mineral has several varieties. Deposits of each group are located on different soil layers and have different formation conditions. The earth's crust consists of 60% feldspar. Most land areas boast the presence of feldspar. Interestingly, the surface of the Moon is also rich in spars. Many meteorites are composed of feldspar.

Human use of spar is developing, so mining is widespread and active. On a production scale, feldspar is mined in the following countries:

  • Kazakhstan;
  • Poland;
  • Japan;
  • Madagascar;
  • Germany;
  • Switzerland;
  • Ukraine.

Going into production jewelry, V large quantities found in other territories: Canadian, Indian and African republics and Brazil. Labradorite was developed in the mines of Canadian, Ukrainian deposits, China, Greenland and Indian lands. Orthoclase pleases archaeologists and miners of the Australian continent, America, Kyrgyzstan, the Italian and Mexican mountains. Adularia was developed in India, the island of Sri Lanka, the Republic of Tajikistan, and Switzerland. The mineral is mined high in the mountains, and the higher the mountainous country, the higher the quality of the gems.

Medicinal properties of feldspar

Feldspar has special healing value for humans. The range of medicinal uses is very wide. But the healing properties of each mineral included in the feldspar group are different. You should carefully study the capabilities of each gem so as not to harm your health.

The healing stone Labradorite provides the following therapeutic assistance:

  • diseases of the supporting apparatus;
  • deviations of the genitourinary system;
  • relieves insomnia;
  • calms the psyche.

Healing properties of microlins:

  1. Improving the functioning of vascular systems;
  2. Normalizes the psyche;
  3. Relieves stress;
  4. Purifies the blood;
  5. Takes you out of depression.

Albit treats kidneys and liver. Andesine is recognized as a powerful antidepressant mineral, comparable in effect to strong drugs.

Magical abilities and powers of feldspar

Feldspar gems enjoy fame magic stones. They are used by light and dark witchcraft forces, mediums and shamans.

Magical abilities of the stone:

  1. Spiritual movement into the past and future;
  2. Development of natural qualities and abilities;
  3. Communication with spirits of other worlds;
  4. Knowledge and understanding of the Universe, connections of planets.

Magical powers of feldspar group stones:

  1. Labrador helps older people. It imparts activity, positivity and optimism. The stone helps to maintain a good mood.
  2. Microlins protect family relationships. Minerals help maintain home comfort and warmth in relationships.
  3. Orthoclase can warn of upcoming changes in relation to loved ones. It changes color. Knowing about such abilities, a person begins to be more patient and attentive. This behavior helps to avoid scandals and quarrels.
  4. Amazonite makes a person bold and confident. Gems change personal qualities. Rude people become reasonable, harsh people become wise.

Talismans and amulets

Adularia can be a talisman and protective talisman. feldspar has magical powers needed creative people and specialties:

  • develops imagination;
  • gives clarity of thought;
  • helps to construct speech clearly and logically.

An amulet made from adularia protects against the impact of energy forces on the human aura black magic(vampires), will protect you from the evil eye.

Interesting video: Sunstone - feldspar

Feldspar colors

All types of stone in natural formation are colorless. The palette of colors is acquired by rocks with admixtures. Shades of orthoclase: pink, snow-white, red and yellow. Microline paints: bright red and orange. The group is called sun stones. They resemble a bright luminary, the surface seems to warm and radiate warmth. Amazonites are endowed with gray and green shades.

Labradorite shimmers with all the colors of the rainbow, the base of the mineral is often blue-black. It is sometimes called a cold rainbow, there are many colors, but they seem to have lost their brightness and saturation, while the shine remains. Iridescence adds an unusual attractiveness to the stone. Orthoclase has pastel colors, you can distinguish the impurity gray. The best samples are transparent in structure and colorless. There are stones with interesting internal contents of the rock: sparks and sparkles.

Adularia is comparable in color to the Moon. Its second name is moonstone. The color is mysterious, the luster of mother-of-pearl is deep. Jewelry stone attracts with the desire to look deep, to comprehend the hidden secret.

How to spot a fake

Jewelry stones are not all feldspars. For feldspar jewelry, crystals with iridescence and a transparent structure are chosen. In the photo of the stone, you can choose any product of the craftsmen. Necklaces are not only beautiful, but noble and discreet. The cost depends on the quality, complexity of the product and the metal of the frame. You can buy all kinds of jewelry. There is no point in counterfeiting them, since the rock aggregates are very common. But the most unique specimens, rare and beautiful, are almost impossible to buy. It's difficult to fake them.

Caring for products with spar

The main application is the ceramic industry. Feldspar is part of the material used to make porcelain. They are easy to care for and should be stored taking into account their fragility. It is not recommended for items to come into contact with each other or other products. Dust and dirt must be removed regularly. Best option – clean water without soap and special household products. It is necessary to dry the products; a layer of dust may again appear on the damp surface.

Feldspar and the zodiac circle

The number of minerals included in the feldspar group is so large that any of the zodiac constellations is compatible and can find an astrological assistant among the gems. Appearance Gems cannot be used as a basis. Astrology has studied the compatibility and significance of minerals for humans.

Who is feldspar suitable for:

  • Labrador – Virgo, Aries;
  • Amazonite – Cancer, Taurus;
  • Adularia – Pisces;
  • Andesin - Lions;
  • Albit - Leos.

The meaning of the stone is described in the sources of astrologers. You can find information about how feldspar affects humans.

According to the horoscope, the mineral does not suit other constellations of the Zodiac:

  • Labrador – Cancer, Capricorn, Aquarius;
  • Amazonite – Sagittarius;
  • Adular - Virgo;
  • Andesine - Gemini;
  • Albit - Aquarius.

Feldspar - properties of the mineral, application and description of the stone

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Data-lazy-type="image" data-src="https://karatto.ru/wp-content/uploads/2017/11/polevoj-shpat-1.jpg" alt="feldspar" width="330" height="223">!} Spar is a common name of ancient origin for a whole group of minerals. Most often used in relation to feldspar, the properties of which are used in crafts and industry. The global significance of this stone, its varieties and features will be discussed further.

Feldspar as a mineral

The name of the term “spar” is borrowed from the German language, where “Spath” literally means “block”. The first thing to definitely mention about this is unique stone, - He main component earth's crust. If we talk about its mass, then feldspar makes up ½ part. Moreover, many rocks are nothing more than a spar variety combined with some mineral. As the stone disintegrates, it turns into clay or other sedimentary substances. That’s why there is so much of it in nature, and geologists even dubbed the mineral “the rock master of the planet.”

Spar minerals are silicates characterized by complex chemical composition. There are three main groups:

  1. Na – sodium;
  2. Ca – calcium;
  3. K – potassium feldspars.

All varieties of the mineral are characterized by perfect cleavage. When stones split, as a rule, fragments of a prismatic shape are formed. Their surface is usually smooth. The hardness is decent, up to 6.5 in the Mohs measurement system. Another interesting property of the stone is layering: crystals can split into plates. This characteristic is called spar in professional circles.

Rock deposits are located in abundance on all continents. Mining is carried out everywhere.

Png" alt="" width="80" height="68"> The only distinction between deposits is the variety of the mineral: for example, adularia is mined mainly in the eastern regions of the Earth - India, Tajikistan. Heliolite development is carried out in the USA, Madagascar, and in the Russian regions of Karelia and the Urals. Labradorite, amazonite are traditionally found in Brazil, Canada, Ukraine, Mongolia, etc.

Precious varieties

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Among all the diversity of this remarkable mineral, there are several gems that firmly hold a high position among jewelry stones. The most valuable from this point of view is the moonstone. Its undeniable attractiveness is formed by the fine fusion of thin layers of orthoclase (pure potassium spar) with albite. The latter is a white sodium silicate. Moreover, the thinner the puff plates, the more noble and beautiful the blue radiance of the moonstone.

Another jewelry representative is heliolite, a solar stone. It shimmers with a yellowish or reddish shimmer. It owes its beauty to iron crystals (hematite, goethite). They are scattered throughout the structure of the host crystal and reflect light, which gives the color play of the stone. The most spectacular shimmer is obtained if the iron inclusions have a scaly shape. This stone is called aventurine feldspar.

Also, such subspecies as andesine, belomorite, labradorite, amazonite, etc. are used as ornamental jewelry material.

Applications of spar minerals

In addition to jewelry, the practical use of stone varieties has been recorded in the following industries:

  • Potassium minerals are essential in the production of fine ceramics and quality window glass.
  • Potassium-sodium compounds are useful in the manufacture of building ceramic products, as well as durable technical glass.
  • Some species serve as raw materials for extracting aluminum and rubidium from them.
  • The texture of minerals of this group is suitable for the production of light abrasives, which has found application in the cosmetics industry and soap making.
  • Some species are used to make mineral paints and rubber.
  • Feldspar minerals are also involved in the production of insulators and electrodes, and cables for technical purposes.
  • Feldspar bars serve as an excellent facing mineral (amazonite, labradorite).

Healing and magical properties

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Since spar is a multifaceted mineral, its magical power manifests itself in different ways, depending on what variety it is presented in. Also in lithotherapy, the types of mineral divided their therapeutic functions:

  1. Feldspars of volcanic origin are a barrier against the evil eye and damage.
  2. Amazonite is a talisman of fidelity and marriage. Has a restorative effect on the heart and nervous system.
  3. Orthoclase is the keeper of family foundations and home. Magicians believe that if orthoclase begins to change color, this is a signal that the marriage is cracking, the spouses are on the verge of divorce.
  4. Moonstone is a concentrator of sensory perception, relieves mental disorders.
  5. Labradorite is a stone of knowledge of the world, an energy accumulator. Strengthens joints, heals reproductive organs.

Also, lithotherapists have noted the effective effects of albite for ailments of the excretory system, heliolite for dermatological problems, andesine for depressive conditions. Cases have been recorded where feldspar helped with epileptic seizures, reducing their frequency and strength. This ability is attributed to orthoclases and adularia. As an amulet, minerals should be presented to people who are fighting cancer.

Spar in astrology

For any zodiac sign there is a talisman among the types of feldspar. In a general sense, the mineral is universal in astrology. But if we add some specifics, the distribution of stones in this group according to zodiac signs looks like this:

  • Labradorite provides support to people born under the auspices of the constellations Aries, Leo, Virgo and Scorpio. Not suitable for Cancer, Capricorn and Aquarius.
  • Adularia, especially in jewelry, is an effective and reliable patron of Cancers and Pisces.
  • Andesine – assistant and stimulant vitality in Aries and Leo.
  • Amazonite is a talisman of well-being for Aries, Cancer, Taurus, Scorpio. But he doesn’t get along with Sagittarius.
  • Albit is the best spar amulet for all zodiac signs, except Leo and all “water” constellations.

These are just a few interesting facts about feldspar. This mineral is infinitely unique. Despite its deep study, it still attracts both scientists and ordinary people. The many faces of the stone are its biggest mystery. And the proven fact that it is on the Moon and other space objects gives it even more attractiveness.

Feldspar is such a common group of minerals that it makes up almost half the mass of the earth's crust. The name of this mineral from the class of silicates consists of the Swedish word feldt, which translates as “field”, and the German spath, i.e. "bar" or "plate". It is called field because it is often found on Swedish arable lands, which are located on moraine deposits. The feldspar mineral is characterized by good cleavage: when struck, it easily splits into plates, hence the “bar” in the name. Humanity has long found use for it in various industries, from industry to jewelry.

Composition and properties of feldspar

To better understand what feldspar is, you should look at its composition. From a chemical point of view, it is an aluminosilicate resulting from the combination of A12O3 (aluminum oxide), Na2O (sodium oxide), K2O (potassium oxide) with SiO2 (silicon dioxide). This composition of feldspar explains its structure: it is characterized by a framework type of crystalline structure and the formation of twin crystals. The mineral can be described as brittle, with an uneven, step-like fracture.

The color of the mineral may differ depending on the type of feldspar: the origin and presence of impurities play a significant role here. For example, orthoclase comes in yellow, white, red, and if the color of the stone is blue-black, then this is most likely Labradorite. In addition to the color of the mineral itself, it is also characterized by the color of the trait, which is also the color of the mineral in powder. In the case of feldspar, this color is white.

On the Mohs hardness scale (from 1 to 10), position number 6 belongs to feldspar, the properties of which are characterized as follows: the stone can scratch glass, it is processed with a file. Rutile and opal have similar hardness. Density varies from 2.54 to 2.75 g/cm³. For reference: oil has the lowest density, namely 0.8 g/cm³, and the highest density belongs to iridium and is 22.8 g/cm³.

Types of Feldspar

Depending on the chemical composition, feldspars can be divided into 3 subgroups:

  • sodium-calcium (plagioclase);
  • potassium;
  • potassium-barium, or hyalophanes.

Soda-calcium feldspars make up a significant portion of metamorphic and igneous rocks. The general formula is (Ca, Na)(Al, Si) AlSi2O8. They are characterized by the twinning effect and triclinic crystal structure. Plagioclases include oligoclase, labradorite, albite, bytownite, andesine, and anorthite.

Potassium feldspar has the formula KAlSi3O8. This type of mineral is of igneous origin and is much stronger than representatives of the plagioclase group. The group includes sanidine, microcline, orthoclase and adularia. All of them have one chemical formula, but the ordering of the crystal lattices differs. They can be distinguished from plagioclases by coloring: as a result, plagioclases will change color to red-brown (except for albite).

Potassium-barium feldspars are very rare and are represented by celsian. Formula - BaAl2Si2O8. The value of these cream-colored stones is exclusively collectible. Note that physical properties minerals of different subgroups are very similar, despite differences in chemical composition.

Deposits and production

Feldspar makes up a significant portion of the earth's crust, so it can be found in many parts of the world. There are many deposits in Russian Federation, here are some of them:

  • Northern Caucasus (Karachay-Cherkessia);
  • North-Eastern region (Chukotka Autonomous Okrug);
  • Southern Siberia (Tuva);
  • Transbaikalia;
  • Kola region (Murmansk region);
  • Southern Urals (Chelyabinsk region);
  • Middle Urals (Sverdlovsk region).

Known large deposits in Sweden, Norway, USA, Ukraine, India, Tajikistan, Japan, Madagascar. Feldspar deposits come in several types depending on the origin of the mineral. The following are distinguished:

  • pegmatite;
  • igneous;
  • sedimentary;
  • weathering;
  • hydrothermal;
  • metamorphogenic;
  • effusive-sedimentary.

Feldspar is mined very actively, because it has applications in a wide variety of industries. It is used to make glass, in ceramics, as a light abrasive, and as a raw material for rubidium. Its role in jewelry is also important: many types of stones are particularly beautiful and are even valued at a tidy sum. In addition, the mineral is credited with magical and healing properties.

Magic properties

Since ancient times, people have tended to attach magical meaning various subjects. Varieties of feldspar are no exception: the beautiful coloring of the stones is of interest to many sorcerers, witches and healers, who find use for the mineral in a variety of practices.

Particularly popular is moonstone, well known for its pale blue color and radiant shimmer. Its other name is adularia. This type of mineral is rare, so albite, sanidine, microcline, labradorite, oligoclase, or even counterfeits made of frosted glass with an iridescence effect are often sold under the guise of moonstone.


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As its name suggests, the stone is believed to have a connection with the Moon, so its power is believed to depend on the lunar phases and reaches its peak at the new moon. Moonstone can attract good luck and protect its owner from evil spells, and will help unmarried girls find their soul mate. In addition, it pacifies anger and promotes relaxation and calm. Moonstone is especially recommended for those born under water signs: Pisces, Cancer, Scorpio. Positively affects such chakras as Sahasrara, Ajna, Anahata, Manipura.

Labradorite, often mistaken for a moonstone, is also suitable for use as a talisman. It promotes the development of intuition and hidden abilities, and helps protect the home from harm. If moonstone is good for young people, then labradorite is more suitable for mature, experienced people. Influences the Manipura chakra.


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Amazonite helps you become more confident and decisive. This turquoise-colored stone reduces anxiety and brings peace, and gives family people harmony in relationships. By its nature, it carries softness and tenderness, so the fair sex should pay attention to it. Amazonite is suitable for Pisces, Capricorns, Virgos and Libra. Positively affects the Anahata and Vishuddha chakras.

Sunstone (special effect orthoclase) has the ability to bring balance to opposites. In addition, it is responsible for vital energy, strength and joy, helps the development of intuition and wisdom. This type of mineral is good for those who lack positive energy and confidence for new endeavors. Suitable for those born under the signs of Leo and Aries. Affects the Manipura, Anahata and Svadhisthana chakras.

Medicinal properties

Lithotherapy (treatment with stones) actively uses varieties of feldspar. The mineral is believed to have a positive effect on the nervous system and help fight stress. Below brief description capabilities of the varieties of this stone used:

  • Amazonite. Massage with amazonite balls is practiced, as a result of which the condition of blood vessels and skin improves, and metabolism is restored.
  • Bull's Eye (Labrador Retriever variety). Helps lower blood pressure and has a positive effect on the genitourinary system.
  • Sanidin. Used for swelling and insomnia. Helps you relax.
  • Albite. Used for diseases of the liver, stomach, kidneys, spleen. It is advised to apply the stone to the area of ​​the affected organ and leave it there for a while.
  • Adular. Used for sleep disorders and overexcitation of the nervous system.

Silver ring SL with alpanite, cubic zirconia and moonstones (go to the SUNLIGHT catalogue)
  • Labrador. Helps treat impotence and infertility, diseases of the genitourinary system.
  • Sun stone (heliolite). Treats nervous disorders, fills vital energy. Helper in the fight against allergies.

This is just a brief description of the possibilities of using feldspar. The bowels of the Earth are infinitely rich and are capable of providing a person with the necessary resources for both industrial needs and for caring for the body and soul, not to mention the material for creative self-expression. Whatever stones you choose, they will share positive energy with you and add a special charm to the owners of jewelry and accessories made from them.

Feldspars are an umbrella term for a group of minerals that form rocks and give rise to sedimentary deposits. The Earth's lithosphere by mass consists of 50% of these minerals and their weathering products (kaolinite, montmorillonite).

Mineralogical composition rocks(intrusive, metamorphic, metasomatic genesis) is 60-65% represented by feldspars.

History, chemical composition and structural features

Why feldspar, why spar? The Swedish geologist Tilas named the mineral Feldtspat in 1740. The fragments of crystals are comparable to plates or bars, hence the name spar (the Greek word “spate” means plate). It was named field due to the frequent finds of minerals in the plowed fields of Sweden (feld - “field” in Swedish).

Geologists have established that the origin of the mineral feldspar is associated with magmatic and metamorphic geological processes.

Magmatogenic genesis: silicate magma melt penetrates into the layers of the lithosphere, pouring out to the surface, or solidifies at depth. The formed intrusions and effusives contain the mineral in large quantities.

Orthoclases of igneous origin are giant crystals overgrown with quartz grains that completely fill pegmatite veins, forming a written structure. The ratio of orthoclase to quartz in pegmatites is 3:1. Metamorphic orthoclases, formed in the contact zone of acidic magma with clays, are coarse-grained, giving the rocks a porphyritic structure.

The ternary system of solid solutions K (orthoclase) – Na (albite) – Ca (anorthite) is represented by 2 isomorphic series:

  • the orthoclase – albite series (the orthoclase component predominates in the crystals, the anorthite content is up to 10%);
  • albite-anorthite series (anorthite with an admixture of albite predominates - sodium feldspar, orthoclase admixtures no more than 10%).

According to their chemical composition, spars are divided into 3 groups:

  • alkaline;
  • plagioclases (aluminosilicate compounds of sodium with calcium);
  • barium.

In addition to the main ingredients, there are admixtures of other chemical elements that give different colors to the minerals. Feldspar minerals, due to their crystallographic lattice structure, belong to framework aluminosilicates.

Their structure is similar to a continuous frame composed of three-dimensional tetrahedrons united by common vertices. Oxygen atoms in the lattice connect silicon and aluminum, being common to them.

Due to the appearance of one free bond in the mineral molecule (the valence of a silicon-oxygen tetrahedron is one unit greater than that of an aluminum-oxygen tetrahedron).

Feldspars formed during the crystallization of magma under dominant conditions high pressure, is characterized by perfect cleavage in two directions, oriented perpendicular to each other. This characteristic is manifested in the splitting of crystals into rectangular bars, tablets, and plates.

Interesting: a transparent variety of calcite with birefringence is also called Icelandic spar. This mineral splits into bars and plates, but unlike the rectangular plates of feldspars, their shape is diamond-shaped.

Alkaline group spars

The isomorphic series consists of orthoclase ("straight cleavage") and microcline ("small angle"). Both are pure potassium feldspar without sodium admixture. The difference between these two minerals can only be seen under a microscope: the cleavage in the microcline does not reach a right angle (it’s just 20 minutes short).

Varieties of orthoclase and microcline are classified as alkaline:

Interesting: all the minerals of the alkaline group are described by one chemical formula (KAlSi3O8), but they have different colors (they are determined by impurities of other chemical elements) and different degrees of order in the crystal lattices.

Plagioclase group and collection minerals

This includes feldspars with a sodium-calcium composition, perfect cleavage also in 2 directions, but at an angle slightly less than a straight line (about 86 degrees), for example:


Among plagioclases there are iridescent ones. Labradorite varieties are endowed with these properties:

  • spectrolite shimmers with rainbow colors;
  • polished samples of black moonstone glow blue from within;
  • have a golden shimmer, which is created by inclusions of tiny particles of iron oxides and aventurine (solar) stones.

Potassium-barium spars are presented:

  • Celsian - colorless, yellowish, creamy, short-columnar crystals;
  • (in total from 5 to 30% celsian).

Barium spar crystals are found in dolomite and manganese deposits; it is very rare and the heaviest - specific gravity 3.4 g/cm3. Beautiful samples are collectible.

Characteristic signs

Feldspar is characterized by the following properties:


The general properties of spars make it difficult to identify minerals by appearance. For precise definition need a microscope. Description of macroscopic differences between plagioclases and orthoclases:

  • different colors (the former have various shades of gray, the latter – from white, yellow to pink and meat-red);
  • relative position of cleavage planes (for orthoclase 90 degrees, plagioclase 86).

An important difference is such a feature as plagioclase twin shading. Labradorite is simply defined as having a color ranging from deep gray to grayish-black with tints of blue-green.

Practical use

The uses of feldspar minerals are as follows:


Feldspars are important not only as rock-forming minerals in rocks. When weathered, they decompose into the mineral kaolinite - valuable white clay, a raw material used in various industries.

Deposits and synthesis of feldspars

Feldspathic raw materials are mainly concentrated in giant granite pegmatites (ceramic, muscovite, rare metal, crystal-bearing). In Russia, reserves (50% of potassium minerals and 40% of oligoclase) are concentrated in pegmatites of the north of Karelia (V. Chkalov mine) and the Baikal region (Naryn-Kuntinsky deposit), Northern Ladoga region and Karelia (Pitkyaranta, Lupikko, Kheto-Lambiny).

Potassium-sodium deposits are known in the Middle Urals (Malyshevskoe) and Eastern Transbaikalia. The largest is the Rezhik deposit in the Middle Urals: here alaskite granites contain up to 45% microcline and over 50% albite with oligoclase.

Alkaline pegmatites are developed in the Vishnegorsk deposit of the Southern Urals near Sverdlovsk, large alkaline spar complexes on the Kola Peninsula (Khibiny and Lovozero nepheline syenites). Belomorite is found along the coastline of the White Sea; Palder (Baikal region), the Ural Mountains, and Utochkino (near Ulan-Ude) are famous for sun stones.

Amazonites are mined on the Kola Peninsula (Keive, Ploskogorskoye, Krasnoshchelye). Pegmatite veins with amozonite are found throughout Eastern Siberia (Ulan-Nur deposit in the Baikal region).

The African continent is rich in Amazonite; large deposits of Hindustan, Canada, and Brazil are known. Ukraine, Chinese Tibet, Finland, India, Canada, Greenland, Germany are famous for their luxurious Labradorite. High-quality adularia is contained in hydrothermal rock veins in India, the islands of Sri Lanka, the Pamirs of Tajikistan, Switzerland, and the USA.

Artificial alkali spar is obtained from glasses using stoichiometric mixing coefficients of chemical elements in the composition (K, Na, Rb, NH4)((Al, B, Ga, Fe)(Si, Ge)3O8). There are 2 methods:

  • dry (synthesis temperature from 700 to 1000 o C);
  • hydrothermal (temperature 550 o, pressure 1 kbar, time 140 hours).

From the proposed set of chemical elements, triclinic (with sodium) and monoclinic (with potassium and rubidium) artificial feldspathic materials were obtained. Synthetic spar with the composition NaFeSi3O8 was not produced by the hydrothermal method; instead, the mineral pyroxene was synthesized.

Monoclinic spar of silver, lithium, and cesium are formed during the ion exchange of sanidine with analbite in the molten chloride of the corresponding element.

Nature has not been stingy beneficial properties for feldspar and its reserves. The deposits are scattered throughout the globe.