These are inedible and very dangerous for life and health stones and minerals. Celestine is a holy name for the stone of angels

Relatively rare, but among the minerals, strontium is the main one.

Latin celestis "celestis" - sky blue (the first samples of this mineral found had a pale blue hue).

Celestine

Chemical composition

Strontium oxide (SrO) 56.42%, sulfur oxide (SO 3 ) 43.58%. Sometimes contains Ca and Ba (often in significant amounts).

Varieties

Baritocelestine contains up to 26% BaO, in calcium-celestine there is a small amount of calcium, replacing strontium.

Crystallographic characteristic

Syngony Rhombic.

Symmetry class. Rhombo-bipyramidal. V. With. V. With. 3L23PC. space group Pnma (D162h). a0 = 8.36; b0 = 5.36; c0 = 6.84. Axis ratio. 1.561:1:1.276, Z=4.

Crystal structure

Completely similar to the structure of barite; the same anionic complex of 2- and strontium (Sr) is present in barium (Ba) positions.

Main forms: t (210), o (Oil), I (102), d (101), s (001), z (211) (Fig. 471). (001) D (101) = 39°24\ (001) D (011) = 52°04", (210) D (210) = 75°58", (001) D (211) = 64°22" .

Form of being in nature

Crystal Shape. The crystals encountered are very similar to barite crystals. Usually they have a tabular, columnar or prismatic appearance, often show blockiness and are prone to splitting.

Aggregates. For the most part, granular, fibrous, dense, rarely columnar or radiating aggregates filling cracks, veiny and shelly. It occurs in the form of secretions, and druses of crystals are observed in the voids.

Physical properties

Optical

Color. Colorless, water-transparent crystals are found, to pale blue or grayish, white, blue, with a yellowish, rarely brown or red tint.

trait. White.

Shine. Glass.

Low tide on cleavage planes mother-of-pearl, silky

Transparency. Translucent, transparent in thin fragments.

Refractive indices / Ng = 1.631, Nm = 1.624, Np = 1.622; Ng = a, Nm = b, Np = c; (+)2V = = 50°, g< v.

Mechanical

Hardness. 3-3.5. fragile

Density. 3.95-4.

Cleavage is perfect according to (001), good according to (210) and imperfect according to (010).

Break. Splintery.

Chemical properties

behavior in acids. In the powder, celestine dissolves in concentrated H2SO4; when water is added, the solution becomes cloudy.

Diagnostic signs

Similar minerals. Cryolite, gypsum, barite, calcite.

In granular masses, we distinguish it from carbonates of Mg, Ca, Sr, Ba, etc. by their behavior in acids (carbonates, when dissolved with heating, release CO2). It is sometimes similar in color to anhydrite, but differs in cleavage directions and greater specific gravity. It is often difficult to distinguish from barite. The reaction to strontium is very characteristic.

Associated minerals. Calcite, aragonite, gypsum, sulfur.

Origin and location

1. Sedimentary

Celestine in more or less significant masses in the form of nodules, nests, sometimes continuous deposits, it is found in the strata of sedimentary rocks (in dolomites, limestones, gypsum-bearing clays, marls, etc.). His finds are often confined to certain horizons among these rocks. A well-known celestite deposit of this type is confined to the Upper Röth deposits in Dornburg near Jena.

It precipitates directly from seawater or from percolating surface water, which leaches strontium from sedimentary rocks and then deposits celestite in fissures as fibrous aggregates or well-formed crystals.

Strontium-bearing gypsum-marl red formation It has great importance. The genesis of deposits is classified as sedimentation-diagenetic. Forms of ore deposits - lenses and layers, length - hundreds of meters and a few kilometers. Celestine is represented by concretions and lenticular formations. Mineralization is confined to the horizons of lacustrine gypsum clays and marls. As V. V. Burkov emphasizes, the considered strontium-bearing horizons are underlain or facies are also replaced by strontium-bearing sulfate-carbonate strata, with partial erosion of which strontium was extracted for subsequent deposition in lacustrine conditions. The deposits are confined to depressions and syneclises of platforms (Iate in Great Britain, deposits of the Mancha depression in Spain, etc.).

Formation of strontium-bearing sulfate-terrigenous variegated deposits represented by deposits with stratal deposits and lenses of celestite ores. Celestine forms concretions, geodes, veins, and is dispersed in the form of individual grains. The most intense strontium mineralization is developed in the underlying gypsum terrigenous units. Among celestine, both sedimentation-diagenetic and later catagenetic are distinguished. Deposits of this formation are known in Central Asia.
The strontium filtration formation in gypsum-bearing-carbonate and sandy-carbonate strata is of great practical importance. The shape of the ore bodies is sheet-like, lenticular, veined. Dolomites, marls, limestones are found among carbonate rocks.

It has also been established in marine organisms, in particular in the skeletons of one group of radiolarians. It occasionally occurs in ammonite shells and other fossils as a result of later deposition in them.

2. Hydrothermal

True, very rare, but typical hydrothermal veins of celestite are known, containing galena, sphalerite and other sulfides.

Formation of strontium-containing polymetallic ores of hydrothermal origin is relatively common, although its industrial significance is small. Celestine and strontianite are obtained mainly as a by-product, although in some places strontium minerals are of leading importance in deposits and sometimes form independent celestite deposits. It is known, for example, the gold-silver-lead deposit of Providencia (Mexico) with an increased mass fraction of celestine in ore veins. Hydrothermal strontium-polymetallic mineralization has been established in the Tunguska syneclise (Russia) and is associated with trap magmatism. The shape of the ore bodies is complex lenses and rods. Strontium minerals are celestine and celestinobarite.
Formation of strontium-bearing fluorite hydrothermal deposits developed relatively widely, but its industrial significance is small. It is known, for example, a deposit on the river. Northern Thompson (Canada), in which the mass fraction of celestine in the ore reaches 22%.

3. Magmatic

It has also been observed in tonsils of igneous rocks.

Place of Birth

Celestine is quite often found in the form of secretions in sedimentary gypsum-bearing rocks of the Permian age, common in the Arkhangelsk region (Pinega river valley), in the Upper and Middle Volga regions with native sulfur (Vodinskoye), in Bashkiria, the Orenburg region, etc. Analogous manifestations are known in Dagestan .

A significant number of locations are also known in Transcaspia (in Turkmenistan (BeineuKyr, Arik), on the island of Mangyshlak (Ungozya)) and other regions of Central Asia.

Note the large deposits of celestine in the areas of Bristol, England; in the Girgenti region), in Girsshagen, Westphalia and Waldeck (Germany).

Stone " celestine"Derived from the ancient Greek" caeletial ", which means heavenly. It was first discovered in Sicily and bore the name "Sicilianite". The crystal received its official name in 1798, thanks to the German scientist Abraham Werner. There are other varieties of it: celestite, bariotselestit, kaltsiotselestit.

Sr sulfate is naturally blue in color. It can be bluish with grayish, yellow, red and brown patches. small size intergrowths of crystals are not too noticeable. However, if they have grown to enormous sizes, they surprise with their beauty and shapes, resembling a flower in similarity.

The crystal found in the natural environment is used in the industrial and jewelry industries. Due to its fragility and short service life, it is quite rare to find it on sale. But still, he finds his admirers among collectors and lovers of stones.

Celestine, its physical and chemical properties

The crystal has a monoclinic syngony, perfect cleavage. Minerals with an irregular fracture, white in powder; with a glassy sheen, turning into mother-of-pearl.

By hardness - from 3 to 3.5

By density - from 2.3 to 2.4

The chemical composition of strontium sulfate: SrSO4. Moreover, SrO accounts for 56.4%, and SO3 - 43.6% of the total mass of the stone. reacts to impurities. When burning, the flame acquires a reddish tint. Quite brittle in structure. Soluble in H2O. Virtually unaffected by UV. Has fluorescent properties.

The first crystals found had a washed out blue tint. A little later, other types of zonal stone were discovered.

Celestine by outward signs similar to barite. But its density is higher than the density of celestine, which is enough to distinguish them without additional chemical studies. In the natural environment, you can often find a compound of celestite Ba, Ka.

The endogenous processes of geological formations and transformations of celestite in the earth's crust show its complex mining and the identification of its crystals. In industry, all non-crystalline stones are used as Sr ore. Their compounds are in demand in the polymer industry, pyrotechnics; nuclear, electrical, glass industries.

Celestine Mining Sites

Madagascar is famous for its soft blue celestines. Unusually beautiful transparent crystals are mined in Australia. Thanks to the stone, Bristol mines are known. The province of Spain is rich in gems of excellent quality, going to the jewelry industry.

In Russia celestine mined in the Volga-Ural region, Yakutia.Buryatia. Fine minerals in Turkmenistan. Ohio stones are considered to be the most valuable. At the end of the 19th century, G. Heinemann, an emigrant and winemaker from Germany, discovered the largest celestite veins to date.

It happened quite by accident when he was digging a well for himself in Put-in-Bay. There he stumbled upon a cavity, almost ten meters long, which inside was littered with outgrowths of meter-long celestite crystals.

The cave of Podolia is open to visitors who want to see celestite crystals. There they are preserved in their original form as opaque and translucent minerals of a bluish-white hue.

Collectors appreciate stones larger than 5 centimeters with high transparency and red-brown color. It is these gems that are found in the northern part of Turkmenistan. But, it is worth noting that, despite all their positive sides, this extraordinary beauty is not suitable for jewelry industry because it is soft and radioactive.

The most courageous and risky jewelers still dare to cut this mineral, but no one exposes it to x-rays. Its ability to accumulate radiation in itself repels many jewelry lovers to the mass production of decorations from this stone.

Pretty hard to find on sale. celestine faceted cut, besides its price is high. For example, a druze made of crystals of the highest class, weighing 70 grams, cut in silver, can cost up to $ 700. A bracelet with big stones opaque celestine will cost up to $10. A ball polished from stone, weighing 2 kilograms, can be bought for $200.

However, the world of decorations for interiors made of celestite is diverse. The most popular is the "crystal with chrysanthemum". On black granite or slate, intergrowths of white celestite. Such beauty can be found in the ore deposits of eastern Asia.

The Chinese invented a legend that explains the appearance of chrysanthemum on ore. Once upon a time on Earth, in its heavenly part, dark forces began to live, who despised the Sun and Earthly magnificence. They turned the Garden of Eden, the water and the valley into mud. The virgin who lives in heaven set the demons on fire. From her flame the soil turned to stone. To return beauty to the Earth, seeds fell from the sky, which sprouted in the petrified thickness. This is how white chrysanthemums were born.

There is a legend about celestine among Europeans. It is associated with the name of the pope of the 13th century. It is assumed that a rosette of crystal with a white flower catches the eye only of the pious righteous.

Celestine, its healing and mystical properties

Some magicians claim that celestine can bestow the oratorical art of his master. He endows positive energy present and raises the reputation of its owner. Women become more seductive, and men are purposeful and assertive.

Mediums stone is used in meditative practice. It gives the opportunity to communicate with otherworldly forces.

With the help of celestine, you can open abilities and talents. For this, lithotherapists are recommended to wear talismans with this stone.

Crystal, like his other "brothers" blue tint, lowers high pressure, has a beneficial effect on the circulatory system and the heart muscle.

The crystal influences the processes of neuroplasticity of the central nervous system, effectively exciting or calming her. Therefore, it is very important that the owner of the stone was able to regulate the behavior of the mineral and resubordinate it according to his rhythms of life. Otherwise, the owner of the crystal may have psychological questions.

Healers claim that with the help of celestine, digestion processes improve. This stone or jewelry with it is advised to be placed in the abdomen. You can buy balls of this mineral and roll them in the painful area of ​​​​the body until you feel better. In this way, the intestines can be cured.

The crystal has a positive effect on the fifth chakra - Vishudha, located on the neck. She is responsible for fellowship, faith, truth and devotion. Through this chakra, people show who they really are.

Celestine and astrology

Gemini astrologers recommend celestine wear as a talisman. The effect on other signs of the zodiac has not been revealed. The Celestine amulet will help creative professionals: writers, artists, designers, architects and all those who have a penchant for creativity.

Properties

Syngony: Rhombic

Composition (formula): SrSO4

Color:

White, colorless, sky blue, grey, greenish, reddish, brownish

Dash color (powder color): White

Transparency: Transparent, Translucent

Cleavage: Perfect

Kink: Uneven

Luster: Pearly, Glassy

Hardness: 3-3.5

Specific gravity, g / cm 3: ~4,0

Selection form

Celestine is represented by elongated prismatic, less often tabular crystals. Celestine usually forms aggregates with parallel or radiantly arranged crystals, as well as massive accumulations of a dense or concretional structure. Celestine often forms pseudomorphs after calcite.

Main diagnostic signs

Celestine powder gives the flame a carmine red color due to the presence of strontium.

Origin

Celestine usually has a sedimentary evaporite genesis. Celestine of hydrothermal origin is less common.

Deposits / manifestations

IN modern Russia strontium is not mined, although there are promising deposits of celestine: the Mazuevka celestine deposit (the village of Mazuevka, the Perm region, the predicted reserves of celestine are up to 7 million tons), the Tabolskoye deposit (Kimovsky district, the Tula region, 3 million tons of celestine have been explored), Blue stones ( in the mountains of Dagestan, 680 thousand tons of celestine have been explored).
In the world, large deposits of celestine (millions of tons) are found in Spain, Iran, Canada, China, Mexico, and Turkey.

Application

Celestine is the main raw material for strontium, which is used to alloy special alloys; in radio electronics, pharmaceuticals, glass and ceramic production, pyrotechnics; previously used in the refining of sugar.

Strontium and its compounds are needed, for example, for the manufacture of special glass that blocks X-rays. For ceramic magnets. As an additive in the production of ceramic capacitors. As an additive to increase the hardness of aluminum and copper. As an ingredient in toothpaste. As an anti-corrosion coating for aluminium, zinc and magnesium aircraft alloys. In fireworks. In the manufacture of luminous paints. Strontium glazes (instead of the previously used lead glazes) adorn porcelain items.

A mineral called celestine is made up of strontium sulfate. The Latin term "celestis" is translated as "heavenly", that is, the name of this stone indicates its delicate blue color. But there are also gray-blue, yellow and even red celestines. All of them are transparent or translucent and resemble in structure. From the latter, outwardly very similar mineral, celestine is distinguished by the color of the flame. While calcining barite in it gives green tint, for celestine under such conditions, a bright Crimson.

Celestine is a common rock, for which many deposits are known on all continents. So, sky-blue crystals are mined on the island of Madagascar, in Austria - transparent. Collectible transparent samples, painted in red-brown tones, are found in the mines of Turkmenistan. In the mountains of Dagestan, rich blue stones are being mined.

Celestine is also mined in Italy and Great Britain, the USA and Canada. Large deposits located in Mexico, China, Iran and Turkey. Suppliers of gem-quality stone samples are Germany and Spain. Russian deposits are also known.

The first Celestines were discovered in the 18th century on the island of Sicily, and they were initially called "Sicilianites". But later this name was considered dissonant, and at the suggestion of the German scientist Abraham Werner, the stone was renamed "celestine". The term is of Latin origin and goes back to the word "caelestis", which translates as "heavenly" and indicates the characteristic blue color of the gem.

The samples found in Sicily just had a somewhat blurred blue color, but it turned out that crystals of celestite of other colors are also found in nature. Nevertheless, the second name for the mineral has been preserved and entrenched in modern mineralogy.

Celestine is composed of strontium sulfate. Its crystals have a monoclinic syngony, perfect cleavage, irregular fracture, glassy or mother-of-pearl luster. Pure strontium sulfate is colorless, and impurities can give it a wide variety of shades.

The hardness of the mineral on the Mohs scale is 2. Density is 2.3-2.4 g/cm3. Fragile, soluble in water, prone to fading in the sun.

When a mineral is added to a flame, it turns reddish. In the presence of impurities in the composition of celestine, fluorescence in the ultraviolet spectrum may appear.

In natural geodes, celestine forms large (tens of kilograms) crystals and large volumes of druses.

Celestine is a positive and benevolent mineral that has a beneficial effect on a person's mood. It is used during meditation. Celestine will endow a male owner with self-confidence, and a woman with a sense of her own charm and attractiveness. Celestine amulets also help women to more easily experience personal dramas, parting with a loved one and gives strength during difficult periods in life. Talismans with this gem are also recommended for overly suspicious and emotional people they will help them to be calm in difficult situations, think clearly when necessary to make quick and correct decisions.

Celestine is also considered the stone of talented people. In them, he awakens hidden opportunities and potentials, endows with eloquence, relieves the fear of speaking in front of large audience. For maximum effect in this direction, it is important to contact the stone every day.

Lithotherapy has so far been little explored medicinal properties celestine. It is known to have a normalizing effect on arterial pressure, improvement of blood circulation and permeability of the walls of blood vessels, relief of rheumatic pains. Celestine is also used in the treatment of eye diseases, the mineral is also used to restore vision.

As for the nootropic effect of celestine, the mineral is used with caution, as it alternates between an increase in mental activity with its inhibition, emotional decline and sleep. So that the strength of the stone affects positively, and the mineral does not have negative impact for health and mental condition, it is important to find a match between the daily rhythm of a person and a gem.

Strontium, the main component of celestine, is used for the needs of the pharmaceutical, ceramic, glass and pyrotechnic industries. In metallurgy, strontium is used to alloy alloys and ensure the hardness of copper and aluminum, as an anti-corrosion coating in aircraft alloys and for zinc. In the twentieth century, strontium was used in the manufacture of sparklers, salutes and rockets. Now strontium nitrate, which is isolated from celestines, is part of the red fireworks.

Occasionally, celestine is also used in jewelry, but it is very difficult to cut and process, and therefore products made from it, as a rule, are single copies. X-ray treatment of celestine is not allowed, as this increases the radiation of strontium atoms, which can cause harm to human health.

The first discovered samples of celestite were painted in a delicate blue color, thanks to which the stone got its name. In general, the mineral is characterized by all shades of blue, and in nature there are gray, yellowish and even red specimens.

Celestine is a very soft and fragile stone, it is stored separately from other stones and protected from mechanical damage, bumps, scratches and chips. For jewelry velvet bags or boxes with soft walls are suitable. If the product needs to be cleaned, use a damp soft tissue. Dry under open sun celestine is not recommended, nor is it generally recommended for long-term exposure to direct sun rays. In bright light and high humidity the mineral quickly loses its qualities.

The real favorites of the Celestine in the zodiac relation are Gemini. As for representatives of other signs of the zodiac, the exact influence of the stone on them is currently unknown. Celestine helps all, without exception, people of creative professions, including writers, artists, designers, designers and architects, regardless of zodiac affiliation.

faceted celestite on jewelry market it is expensive because it is rare. Collectible specimens of this stone are more common. For example, the cost of a quality druze weighing 70 grams, set in silver, is 500-700 dollars. A ball carved from celestine, weighing about 2 kg, is valued at $ 200. But a bracelet made of large beads of opaque celestite is inexpensive: 8-10 dollars.

Celestine decorations for the interior are very popular today. In this regard, "chrysanthemum stone" is in demand, which is small but beautiful intergrowths of celestines. Rosettes of sparkling crystals look great white color against a background of black granite or slate.

• On the territory of Ohio in the United States, there is the largest celestite geode (“Crystal Cave”), which reaches a diameter of 10 m. Now it has been equipped as an object for visiting tourists, and among the celestine crystals there are samples about 1 m long.
• According to the Chinese legend about the origin of celestine, once in one of the most beautiful places Our planet was inhabited by demons who hated beauty. They filled everything around them with liquid mud. But the powers of heaven burned the demons, and the soil at the site of the conflagration turned to stone, and seeds fell from heaven onto the damaged earth, which became sprouts in the thickness of the fossils. It is these sprouts that are celestines.
• In Europe, the Celestines were associated with a different story. The name Celestine in the Middle Ages was the personification of light, purity and infallibility, as it was worn by a Benedictine monk who lived in the 13th century, led a hermit life and was elected pope, but renounced his high rank. It is believed that a stone rosette of the mineral celestine, similar to a chrysanthemum, is able to reveal its beauty only to a holy righteous man.

The mineral belongs to natural strontium sulfates. Its name comes from the Latin "celestis", which means heavenly and corresponds to the color. The Celestine stone has unique properties, has a meaning and influence on the signs of the zodiac. In fact, not only blue minerals are found in nature, but also red, yellow and gray samples.

It is worth noting that a feature of the stone is a similar structure with barite. By appearance they can be confused, but when exposed to fire, barite changes color to green. Celestine takes on a rich crimson hue.

According to its structure, the stone is characterized by fragility and irregular fracture. Also under the influence of ultraviolet Celestine loses its original beauty, the color disappears.

The chemical formula is Sr(SO 4).

Story

The first copies of the mineral were known to mankind in the eighteenth century, a deposit in Sicily gave the idea for the name. But the German scientist A. Werner considered that the cacophony could be replaced by today's version, which took root.

This event took place in 1781.

There is a legend in Europe that in the Middle Ages the mineral was personified with purity and holiness, because celestine was a favorite adornment of a Benedictine monk who lived in the 13th century, he led a hermit life and renounced his dignity.

Place of Birth

It should be noted that the stone belongs to common minerals. Its deposits are located in Madagascar (blue gems). Austria boasts excellent transparent specimens. It is worth noting large deposits in California, Michigan, Italy and England. In the territory Russian Federation deposits can be proud of the Perm Territory and the Tula region. Beautiful red-brown samples are mined in Turkmenistan, and blue ones are mined in Dagestan.

Origin

The mineral is attributed to a hydrothermal origin, which is formed during the drying of reservoirs with salt water, in which the main component is strontium. In rare cases, the formation of pseudomorphs with gypsum crystals occurs. Sometimes it can be found in ordinary cracks rocks, celestine can form crusts on their surface.

It is worth highlighting the fact that in nature crystals are more often found in large sizes, the aggregates of which can reach 50 cm in length. Sometimes the mineral is formed in sedimentary rocks, which is not uncommon at the bottom of the sea.

Legend

According to Chinese tradition, the formation of minerals took place in a different way. One of the heavenly corners of the earth was visited by terrible demons who polluted everything. The gods had no choice but to destroy the heavenly place along with the demons. To restore nature, it was necessary to scatter amazing seeds, from which celestines sprouted.

Practical use

• One of the main components of the mineral is strontium, which is actively used various industries, in particular industrial and pharmaceutical;
• Also found use in the manufacture of ceramics, glass and pyrotechnics;
• It is actively used by metallurgy, since strontium helps to harden copper and is one of the components of anti-corrosion coatings;
• To date, strontium nitrate, which scientists have learned to isolate from the mineral, is included in the components of fireworks and fireworks;
• It is worth noting that jewelers practically do not use it to make jewelry, since the most qualified specialists. X-ray treatment is not suitable for him, since strontium enclosed in celestine will have an effect on a person negative impact. Jewelry from amazing stone are rare and not put on a serial stream.

magical effect

• Thanks to the benevolent and positive vibrations of the stone, the mood of others will change for the better, besides, it is used by yogis for meditation;
• Recommended for men who feel confident and important;
• For women, it is useful in that it helps to reveal the inner charm and makes them more attractive in the eyes of the opposite sex;
• Regular contact with the mineral should be kept by talented individuals, whom the stone will help to show hidden talents and unlock potential
• Celestine will be useful for people who often perform in public. The owner will gain eloquence, and get rid of the fear of a large crowd of people;
• The stone is great as a talisman. He will add moral strength to women in order to survive various serious situations or a break with a man. In particular, he will raise the morale of weak and shy people, endow them with the ability to quickly navigate in extreme situations and think correctly in the right direction;
• Celestine is recommended to be worn by a designer, writers by an architect.

Influence on the signs of the zodiac

Mineral favorites are Gemini. But the study by astrologers of the effect of stone on other signs is still being studied. One thing is known - Celestine is universal and suitable for everyone.

Therapeutic effect

Lithotherapists are still studying amazing mineral, but some information is still known.

• It helps hypertensive and hypotensive patients to normalize blood pressure, improves blood circulation;
• Regular contact will help reduce pain in rheumatism and other joint diseases;
• It is also suitable for improving vigilance, it is enough to peer into its depth several times a day;
• Given the nootropic properties of the stone, it should be handled with care, since the vibrations of celestine can change the stages of inhibition with increased mental activity. To get help from Celestine, it's important to get in touch with him. Otherwise, a person may be visited by insomnia and nightmares.
• The mineral should also be worn by people who care about their figure and health.

How to care

It is worth noting that the gem is not hard or durable, because it is easy to scratch or break. It should be stored in a separate box with a fabric backing. Do not clean it under running water. Soft enough wet wipes. It also cannot be exposed to ultraviolet light.

Price

The cost of minerals on the market is high, as collection samples are more in demand. For example, a druse weighing about 100 gr. in a silver frame will cost no more than $ 700. A two-kilogram ball will cost $200. Bracelet no more than 10 dollars. More often bought items for interior decoration.