Bath stones: which ones are better to choose and how to use them?

In a Russian bath, and not only in it, thick soft steam from tiny particles of water plays a key role along with the correct temperature. And to get such steam, you need stones. And not just any kind, but of a suitable type, without defects and placed in the oven in compliance with the rules.

Although the right stones are important, not every person has the time or desire to understand all the intricacies of their selection and installation. Moreover, there is often conflicting information on the Internet. Therefore, we decided to make a short guide to bath stones, collecting in one place basic information about their properties and use. We hope it will make your choice easier and bring clarity to the questions you were looking for answers to.

Medicinal properties

The beneficial properties of dunite for use in a bath are based on the presence of olivine in it (of which dunite contains much more than in another widely used bath stone - dolerite), which has pronounced medicinal properties.
Bath procedures with dunite:

• normalize cardiac activity;
• reduce blood pressure;
• increase immunity;
• strengthen the nervous system;
• help with colds;
• used for eye diseases;
• used for diseases of the musculoskeletal system;
• disinfect problem skin;
• increase libido in men.

Specialists from the Institute of Mineralogy of the Ural Branch of the Russian Academy of Sciences gave the highest rating to dunite as a stone for use in baths and saunas.

Dunite is a natural air purifier that has a unique property: when heated in a bathhouse, this stone reacts with carbon dioxide and, thus, purifies the atmosphere in the room, eliminating the appearance of foreign odors.

How and why are bath stones used?

Like many centuries ago, stones in a modern bath or sauna are used to create steam. Saturated and healthy steam is formed when hot stones come into contact with water. To do this, the stones are heated to a high temperature using a furnace. In addition to generating steam, stones also perform another function. Thus, naturally possessing heat-accumulating properties, many types of bath stones accumulate heat and gradually release it into the surrounding space. This property makes it possible to enhance the thermal characteristics of the stove itself, and also increases the duration of bath procedures. Often, thanks to the combination of a good stove and stones, the heat in the steam room is maintained even the next day after the evening heating. And, of course, the stones in the bathhouse also perform an interior function - they are aesthetically beautiful, they add beauty to the design of the steam room - if the stove has an open design.

So, let’s summarize the three main functions of bath stones:

1. Generating abundant steam
2. Accumulation, preservation and release of additional heat
3. Aesthetic beauty

Composition of nepheline syenite

The mineral composition of nepheline syenite is a conglomerate of a dozen components:

• The two main ones are potassium feldspar (65–70%) and grayish granular nepheline (a mineral of the feldspathoid group, up to 20%). The amount of nepheline fluctuates, increasing due to the displacement of spar. In urtitis, for example, there is no spar at all.
• The chemical composition is supplemented by zirconium and titanosilicates (titanite, sphene, astrophyllite, lamprophyllite, enigmatite), rare elements with compounds of chlorine, fluorine, and phosphorus. These are accessory minerals (almost “accessories”, that is, “extras”). They are characterized by the fact that they are contained in large quantities, but do not particularly affect the properties of the stone.
• The third segment in the composition of syenite is colored minerals (biotite, alkali pyroxene, amphiboles). Their presence is possible in small concentrations (total – 6–14%). They determine the color of the stone.

Syenites and their effusive counterparts typically include alkali feldspars and biotite. Other dark-colored trace minerals are rare.

Medicinal properties

The beneficial properties of dunite for use in a bath are based on the presence of olivine in it (of which dunite contains much more than in another widely used bath stone - dolerite), which has pronounced medicinal properties.

Bath procedures with dunite:

• normalize cardiac activity;
• reduce blood pressure;
• increase immunity;
• strengthen the nervous system;
• help with colds;
• used for eye diseases;
• used for diseases of the musculoskeletal system;
• disinfect problem skin;
• increase libido in men.

Specialists from the Institute of Mineralogy of the Ural Branch of the Russian Academy of Sciences gave the highest rating to dunite as a stone for use in baths and saunas.

Dunite is a natural air purifier that has a unique property: when heated in a bathhouse, this stone reacts with carbon dioxide and, thus, purifies the atmosphere in the room, eliminating the appearance of foreign odors.

Economic use

Dunite deposits are found everywhere. It is known about its large deposits in the mountains of the Urals and the Caucasus. It is also mined in the USA, Central Asia, and Ukraine. The rock is not the subject of mining, but remains as an accompanying rock for several metals:

Dunite is used as a fertilizer in potato fields with highly acidic soil. To do this, it is mixed with peat in a 1:1 ratio.

This mineral also serves as a refractory mold for casting metals. When clay is added to it, it can withstand heating up to 1700 C.

Dunite is widely used in baths and saunas. It can serve as both a decorative finish for the stove and its filling.

Interesting things about the stone

1. The best variety of dunite for use in a bathhouse is Ural. The stone should be placed on the bottom of the oven under layers of other stones used for therapeutic purposes. This increases the overall healing effect, since dunite heats up quickly and retains heat for a long time. Use with white quartz and Himalayan salt promotes air ionization and creates a cozy microclimate in a home bath.
2. The thermal stability of dunite is due to the low content of volatile substances in the composition. When heated, the stone can only lose 1.5% of its mass, so it does not crack.
3. Dunite can be ground quite easily into sand. In this case, olivine grains take on the role of grains of sand.
4. In past times, mineralogists believed that dunite could contain diamonds and platinum. There is unconfirmed evidence that such isolated finds have taken place, but over the past decades, despite intensive searches, such a breed has not been found.
5. A separate advantage of the stone is its beautiful and unusual texture. Dunite has a huge number of shades and contains a variety of decorative inclusions, which naturally finds application in design.

Popular minerals and their characteristics

The characteristics of the stones most suitable for use in baths are listed below:

Chromite

Heat capacity kJ/kg*С0 - 0.92

A natural mineral of igneous origin, 90% consisting of chrome spinels. It contains olivine, serpentine and pyroxene, and may contain Mg and Zn elements.

It has a high specific gravity, heat capacity, strength, is non-toxic and does not interact with the liquid medium even at high temperatures.

The stone has long been used in folk medicine to treat pathologies of the reproductive system. It has powerful energy, improves immunity, and treats colds.

Soapstone chlorite

Heat capacity kJ/kg*С0 - 0.98

Eco-friendly material that has the ability to retain heat throughout the day. Allows you to obtain a large amount of steam with a minimum number of cobblestones. Before first use, it requires piercing and washing, which eliminates the formation of dust.

It has a lot of healing properties: strengthens the body, adds vitality, increases immunity, promotes the synthesis of vitamin D in the body, and normalizes metabolism. Soapstone emits soft heat, similar to that of the sun.

White quartz

Heat capacity kJ/kg*С0 - 0.75

The material is not very strong and durable, it can crack when heated, but it has excellent aesthetic qualities. The translucent white minerals look stylish in the oven and produce a lot of steam.

A distinctive feature of white quartz is the release of fragrant ozone upon sudden cooling after heating. The mineral stimulates brain activity, has a beneficial effect on the nervous system and enriches tissues with oxygen.

Dunit

Heat capacity kJ/kg*С0 - 1.00

The black rock, consisting of olivine and pyroxene, does not emit harmful impurities when heated.

It has a low coefficient of linear expansion and high specific heat capacity. Thanks to this, it does not crack and can withstand high temperature loads.

The stones do not have decorative properties, but their natural irregular shape provides a large area of ​​evaporation. By interacting with carbon dioxide, peridotite purifies the air, helps cure colds, and stabilizes blood pressure.

Quartzite

Heat capacity kJ/kg*С0 - 0.70

Durable, wear-resistant cobblestones with high density and low water absorption. Quartzite does not lose its external qualities during prolonged use, does not crumble and does not emit harmful substances.

It comes in crimson, yellow and gray colors. Useful in the treatment of vegetative-vascular diseases and pulmonary pathologies. Helps improve blood circulation, normalizes blood pressure, and heals joints.

Basalt

Heat capacity kJ/kg*С0 - 0.84

Basalt or vulcanite is naturally durable and resistant to high temperatures. It has very low water absorption properties and has a high heat capacity.

The mineral is capable of intensively generating healing steam. Increases blood pressure, helps with colds, joint inflammation, migraines, nervous system disorders and eczema.

What it is?

The likelihood of a person encountering dunite is low. It happens, of course, that tectonic processes bring it and other ultramafic rocks to the surface, but by now they have time to undergo metamorphoses that change both the composition and properties of the stone, so that the only thing you can find in nature in nature is former dunite, which has turned into serpentinite

Stones for baths and saunas Dunit, 20 kg. Photo by Leroy Merlin

So we take the risk of answering the question “what is dunit?” analogy: it is something like a deep-sea fish that is rarely seen on the surface. However, if mining turns out to be profitable, then both stones and fish will quickly end up on the counter.

Mineral or rock?

For those who believe that the correct scientific name for a rock is "mineral", the news is that the rocks are actually more like, say, a stew - like a stew, they are made up of many ingredients, the pieces of which are different from each other, these are the minerals, and all the “stew” together is the rock.

Mineral composition

The main mineral of dunite is olivine. Its amount in the limit is 90%, which makes dunite similar to monominerals. And the remaining 10% went to chromite or ilmenite, or titanomagnetite and impurities, which made it different from olivinite - it also consists of 90% olivine, and the remaining 10% is magnetite and impurities.

Thus, dunite and olivinite are practically the same thing, with the difference being whether chromium or titanium oxide is present in the iron oxide diluting almost pure olivine (magnesium iron silicate). As for olivine itself, in reality the ratio of magnesium and iron silicates in it is quite variable and is in the range between forsterite (pure magnesium silicate) and fayalite (pure iron silicate).

By the way, there is a gemstone - peridot, which is simply a transparent variety of olivine. Another name for it is “peridot”.

There are also less concentrated varieties of dunite: chromite, ilmenite and magnetite. The question immediately arises: if magnetite dunite consists of olivine and magnetite, then how does it differ from olivinite? And it differs in that, firstly, it contains not just magnetite (which is a natural iron oxide), but titanomagnetite (iron oxide and titanium oxide), and secondly, the percentage ratio of olivine and titanomagnetite differs from olivinite : not 90% of olivine, but only 70%; accordingly, titanomagnetite and accessory minerals will account for 30%.

The stone blows. Photo Fire stone

What is called chromite dunite is also not identical to that described above, but the difference is only in percentage: there, too, the proportion of olivine is reduced to somewhere around 70%.

Ilmenite dunite is another variety with titanium oxide in the form of the mineral ilmenite, the breakdown of which, by the way, gives life to titanomagnetite. The ratio of olivine and ilmenite is close to that described above.

In other words, fluctuations in the chemical composition of magma, while it follows certain laws of sequential crystallization and destruction of minerals, ultimately gives a number of discrete varieties of rock that have their own names.

The crystallization sequence is also responsible for the formation of facies, at the boundaries of which the presence of pyroxenes in the mineral composition of dunite is possible.

This is how the composition of minerals and impurities of olivinite and dunite is described in the Petrographic Code of Russia:

Dolerite stone: properties, applications.

Dolerite is a stone whose properties are not fully used by people. Moreover, many have not even heard of the existence of such a mineral. And those who know the name usually associate it with Yakutia or Kamchatka. People familiar with the mineral are often convinced that it is one of the bath stones and nothing more.

Meanwhile, dolerite is a stone whose properties are not at all limited to the healing effect during bath procedures. And its deposits are found not only in Yakutia, they are scattered all over the world. For example, one of the oldest and most famous is located in the United States of America, in Arizona. This suggests that the mineral played an important role in the culture and religious rituals of the indigenous people of the West.

However, the history of dolerite is connected not only with the Indians, but also with other peoples. For example, the very name of this stone refers to Greek culture.

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About the name of the mineral. The dolerite stone was not always called that way. It was formerly known as diabase. However, it is impossible to say that the mineral has changed its name. Both names were in use, but one of them has lost its relevance today. In France, for example, the mineral is still called diabase.

Both names come from Greek, but have different meanings:

However, many geologists and esotericists argue that diabase and dolerite are different minerals, although similar to each other. In ordinary life, it is also quite possible to get confused in the names. For example, in stores selling bath stones, dolerite and diabase are often presented as different minerals.

Since there is no final point in the dispute between scientists and mystics about the name and varieties of the stone, it is worth considering it not as two different ones, but as one mineral. Which meaning is more suitable for the stone? This can only be judged by familiarizing yourself with its history, application and, of course, the list of properties.

How many varieties of this mineral are there?

Geologists today know more than thirty-five varieties of stones known as dolerites, or diabases. However, it is very difficult for people who are far from scientific studies related to minerals to distinguish between them without explanations from specialists.

In other words, the differences between different types lie in characterizing little things that are noticeable only when examining the stone through a magnifying glass. At the same time, you also need to know what exactly to look at. The varieties are determined by the peculiarities of rock formation, which are inherent in a particular deposit. That is, Yakut dolerite will differ from that mined in Arizona or Wales in its structure and composition. The impurities added to the main rock will vary, as will the grain size.

What was this mineral used for in the old days?

As a rule, minerals are perceived as talisman stones, material for various crafts, bath procedures, massage and, of course, for making jewelry.

However, the hardness of dolerite allows it to be used not only for the above purposes. Furniture, statues were made from it, buildings and altars, and occult structures were built. They even paved the squares.

For example, the Vorontsov Palace, located in Alupka, was built from local Crimean dolerite. Red Square in Moscow was once paved with it. Most of the statues presented in museums at exhibitions dedicated to the culture of the ancient Egyptians are made of dolerite. For example, the world famous black statue of the “Seated Pharaoh”, depicting Neferhotep the First, is made from this stone.

The world-famous Wonder of the World, located in England, in the county of Wiltshire, is made of dolerite. Of course, we are talking about Stonehenge. The stone boulders that form this structure are nothing more than large pieces of mineral, lightly polished by humans.

If you don’t delve into antiquity, you can remember memorial plaques, monuments on the city streets of Europe, black serving tables from the beginning of the last century and much more. This stone is also used in funerals, monuments are made from it, and graves are decorated with it.

However, its use in architecture, art, urban planning and even in everyday life does not make the mineral a material devoid of mystical properties. The stone has powerful energy and has a significant impact on the health, well-being and fate of the person who carries it with him.

Healing properties of the mineral:

Dolerite is a stone whose properties have a profound effect on the human nervous system. Even a careful look at a piece of furniture or some trifle, a decorative figurine made of this mineral already calms. And with direct contact with the human body, its influence increases many times over.

This is probably why many Muscovites love to walk along Red Square, and tourists who have visited the Vorontsov Palace note the special, peaceful atmosphere that fills the rooms. It is probably because of this property that people are so attracted by the mysterious boulders of Stonehenge, and those who are interested in the art of Ancient Egypt pay special attention to the feeling of “quiet grandeur” that emanates from the black statues.

In addition to its beneficial effects on the human nervous system, the stone has the following effects:

The mineral normalizes blood pressure, stabilizes heart function, relieves stress, relieves fatigue, and neutralizes attacks of irritability, aggression and anger.

In East Asia, balls made from this mineral have been used since ancient times to massage the feet. However, even today, anyone vacationing in Thailand or the South-East of China can try massage procedures performed with balls made of this stone.

How much have the mystical properties of the mineral been studied?

Dolerite is a stone whose properties, on the one hand, have been studied very well, but on the other, are completely unknown.

For example, no one can answer the question of why Stonehenge was built from this particular stone. Explanations for the choice of material due to its availability or ease of processing do not stand up to criticism. Dolerite does not lie everywhere on the surface waiting to be used. And the deposit closest to Stonehenge is very far away even by today's standards.

People will probably never be able to find out how and why the indigenous people of North America used the mineral. The choice of dolerite as a material for some Egyptian statues will also remain unclear. After all, not all figurines of cats, gods or pharaohs are made of this stone.

However, everything that relates to the interaction of the mineral and human energy is absolutely known. Therefore, it will not be difficult to understand whether it is worth using this mineral as a talisman.

How does the mineral interact with humans?

Dolerite is a stone, the photo of which fascinates with its beauty, mystery and inexplicable feeling of power emanating from the mineral. Of course, every person, looking at the pictures, involuntarily thinks about purchasing for himself any product made from it.

However, the mineral is not suitable for everyone. The stone is “in love” with active, optimistic, impulsive, strong-willed, decisive and energetic people who know how to value themselves. Products made from it are contraindicated for “quiet” people, shy people who have a negative attitude towards changes in life. The mineral is not suitable for those who suffer from low self-esteem, do not have confidence in their actions, and do not know how to make decisions and take responsibility for them. The stone is not suitable as a talisman for passive, lazy people who are not inclined to take initiative.

Properties, who is suitable according to the zodiac and what is combined with:

How is this mineral useful? This is a very important question, because stones have completely different effects on a person’s energy, his destiny and emotional state. Products made from natural minerals can both attract something good and necessary to a person, such as money, and take it away.

What will attract dolerite into a person’s life? The properties of the stone are as follows:

The stone is “friends” with jasper. Together they form a powerful energy ring that protects a person and directs his activities in the right direction.

Who is this mineral suitable for according to their zodiac sign? The answer to this question is very simple - everyone. Every person can wear a dolerite amulet, regardless of which zodiac constellation he was born under. The stone belongs to the ancient, so-called “primary” energy sources. Therefore, its suitability is determined not by the influence of the stars, but by the type of person’s personality, the qualities of his character.

How should you wear this mineral?

In the windows of Russian jewelry stores offering jewelry with natural minerals and gems, you can often see Yakut dolerite in earrings, pendants, brooches, and bracelets. In Western Europe, cufflinks, tie clips and scarf pins decorated with this stone are extremely popular. You can see other types of jewelry with this mineral.

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Such diversity involuntarily raises the question of how to properly wear products with dolerite? After all, each stone “loves” its specific place. Depending on where the mineral is located, its properties and intensity of influence change.

There are three places on the human body that this stone “prefers”:

The mineral is worn around the neck if it is necessary to achieve success in a new endeavor, for example, starting a business, or successfully passing an interview, or going somewhere. In other words, the stone should be worn around the neck when there is something unknown, new for a person, something in which there is no experience.

On the left, the mineral is worn if necessary:

It makes sense to wear a product with this stone on the left even if you need high-quality and clear advice from a specialist, for example, a lawyer or real estate agent.

On the right, the stone is placed in exceptional and dangerous situations. For example, if a company is facing bankruptcy or is facing a court hearing, then you should wear a product with a stone on the right.

What is a mineral?

He is quite unique. And it is precisely this that explains both its unique properties and the breadth of its applications.

Dolerite is a type of basalt. That is, the stone was formed many millennia ago in the vents of active volcanoes. And this means that he absorbed all the power and greatness of the fire element, all its indomitability.

The composition of the stone is dominated by:

Various impurities are added to them. Their presence and variety depend on the place of formation of the mineral.

Using minerals in baths: advantages and disadvantages.

The use of the mineral in bath procedures is determined by what dolerite is made of. The use of stones in baths depends on their density and heat resistance. The composition of this mineral is ideal for such use.

The most famous variety of these stones among bathhouse attendants is gabbro-diabase. It is a volcanic rock of Cainothyr origin. Outwardly, dolerite for a bathhouse is not particularly attractive, which is not surprising, because the stones are not polished, not processed in any way and are sold in “small wholesale”. The difference with the minerals that adorn jewelry is colossal. Bath stones are dark minerals with whitening veins, giving the impression of being covered with a layer of “age-old dust.” It is not always possible to even understand that they are not gray.

However, in this case the impression made is very deceptive. Dolerite for baths has unique properties; it simply has no analogues. The most important of them are:

Dolerite can withstand at least 300 cycles of instantaneous temperature changes without any changes, completely maintaining its integrity.

However, professional bathhouse attendants rarely use this mineral alone; they usually combine it with other stones. This is done because dolerite heats up very slowly. Although it retains heat much longer than all other types of bath stones, its single use, so to speak “solo”, is not practiced by specialists.

Other disadvantages of this mineral include the following:

Traces of oil cannot be removed from the surface of dolerite. No modern remedy will help with this. They do not go away over time either. Of course, for your own personal bathhouse, this nuance is not a significant drawback. But if we are talking about publicly accessible places, then this property of the stone is extremely important. After all, it is impossible to explain to visitors that minerals are not dirty. People are quite squeamish and are unlikely to visit a bathhouse in which the stones are constantly splashed with something.

How durable is this mineral when used in a sauna?

Dolerite can withstand 300 cycles of sudden temperature changes, but after that it is destroyed. Cracks form on the stones, and subsequently the mineral splits into several parts.

This feature has led to the fact that many owners of public baths have a “related business.” That is, from fragments of deteriorated dolerite, various amulets, amulets, and jewelry are produced. Often they do not do this themselves, but sell the waste mineral to art workshops or to craftsmen working privately. Of course, a product with such dolerite does not have any magical or healing qualities. The stone that cracked in the sauna has already given people everything it could; it not only lost its properties, but in fact the mineral “died.” Therefore, when purchasing products with dolerite, you need to be very careful and extremely careful. Although such decorations, of course, will not cause harm, they will not bring any benefit either.

As for the service life of the mineral in saunas, bath attendants limit it to two years. Of course, the shelf life of dolerite directly depends on the frequency and intensity of sauna use.

At the moment of destruction, the stone literally “gives up its spirit.” As dolerite breaks into pieces, it releases a “cloud” of sulfur, filling the room with a specific pungent odor, which is very difficult to get rid of. Particularly impressionable people say that the stone actually “dies” in the same way as any living creature does.

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Source

What to replace

Dunite can be replaced by members of the peridotite family, the most common of which is olivine. Pyroxenites, such as jadeite, are also perfect. Its disadvantage is the high price.

In the same price category as dunite are:

All of them are suitable for use in baths.

Advantages of dunite:

• the stone heats up quickly, releases and conducts heat evenly, and does not expand;
• has fire-resistant properties, can withstand temperatures up to 1200 C, so you don’t have to worry about cracking;
• does not emit odor when heated;
• helps restore the nervous and musculoskeletal systems, has a beneficial effect on the condition of the skin and hair;
• interacts with carbon dioxide, protecting you from poisoning.

Flaws:

• unpresentable appearance due to the limited color range from gray, gray-green to black;
• short service life, approximately 6 years;
• transformation from strong dunite to porous serpentine;
• some stones have large inclusions of sulfur, which, under the influence of temperature and humidity, is formed into hydrogen sulfide acid;
• a large number of fakes on the market;
• most often has a small size.

Application

Jadeite is widely used due to its wide characteristics and unique properties.

Jadeite is used quite often as a facing material. Due to its original color, it is used for stoves, walls, floors and swimming pools, which is especially important for saunas. Working with facing jadeite is difficult, so the master must be experienced. The stone used for lining pools is rubbed to a mirror shine. In this form, it becomes noble, looks stylish and luxurious.

• Jadeite has been used as a filler in sauna heaters for a long time. Moreover, it is more suitable for these purposes than other natural minerals. Pouring a small amount of water onto hot stones produces light, soft and pleasant steam.
• Lithotherapy with jadeite is becoming an increasingly popular procedure, which is provided by all self-respecting spa centers. Jadeite is credited with a number of healing properties: filling the body with energy and vigor;
• normalization of pressure;
• beneficial effect on the nervous system.

For more information about the stone, see the following video.

Links[edit]

• Sorensen, H. 1974. Alkaline rocks. 1st edition. John Wiley & Sons Ltd. 634 pp. ISBN 0-471-81383-4.
• Streckeisen, A.L. 1978. IUGS Subcommittee on Igneous Rock Taxonomy. Classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilite rocks. Recommendations and suggestions. Neues Jahrbuch für Mineralogie, Abhandlungen, 141, 1–14.
• Motoki, A., Sichel, S.E., Vargas, T., Ayres, J.R., Ivanuch, V., Mello, S.L.M., Motoki, K.F., Silva, S., Balman, A., Goncalves, J. 2010. Geochemical evolution of felsic alkaline rocks of the Tangua, Rio Bonito and Itauna intrusive bodies, State of Rio de Janeiro, Brazil. Geociências, Rio Claro, 29–3, 291–310.
• Motoki, A., Araujo, A.L., Sichel, S.E., Motoki, K.F., Silva, S. Differentiation process of nepheline syenite magma by assimilation of continental crust for the Cabo Frio Island intrusive complex, Rio State de Janeiro, Brazil. Geociências, Rio Claro, 2011, in press.

Attribution

This article incorporates text from a publication now in the public domain: John Smith Flett (1911). "Nepheline-syenite". In Chisholm, Hugh (ed.). Encyclopedia Britannica (11th ed.). Cambridge University Press.

History and origin

Being a deep-seated igneous rock, dunite is formed at the initial stages of lava differentiation, when olivine and, in some cases, chromite crystallize from the melt. Settling at the bottom of the magma chamber, the mineral forms an almost monomineral rock.

Mineral – Dunite

The main component of dunite is olivine - it consists of 85-90% of it, which determines the color of the stone, which varies from dark gray to almost black and from yellowish-green to dark green.

Under the influence of weathering, olivine, which is part of this rock, is transformed into serpentine and partially into magnetite. Dunite can rarely be found in an unaltered form: as a rule, it is largely serpentinized or even completely transformed into a serpentine. Chromium and magnetic iron ores are also often found in dunite.

Typically, dunite is found in the lower layered horizon of the main intrusions.

Interesting things about the stone

1. The best variety of dunite for use in a bathhouse is Ural. The stone should be placed on the bottom of the oven under layers of other stones used for therapeutic purposes. This increases the overall healing effect, since dunite heats up quickly and retains heat for a long time. Use with white quartz and Himalayan salt promotes air ionization and creates a cozy microclimate in a home bath.
2. The thermal stability of dunite is due to the low content of volatile substances in the composition. When heated, the stone can only lose 1.5% of its mass, so it does not crack.
3. Dunite can be ground quite easily into sand. In this case, olivine grains take on the role of grains of sand.
4. In past times, mineralogists believed that dunite could contain diamonds and platinum. There is unconfirmed evidence that such isolated finds have taken place, but over the past decades, despite intensive searches, such a breed has not been found.
5. A separate advantage of the stone is its beautiful and unusual texture. Dunite has a huge number of shades and contains a variety of decorative inclusions, which naturally finds application in design.

Interesting things about the stone

• The world-famous sphinxes on the University Embankment in St. Petersburg are carved from syenite and are about three and a half thousand years old.
• Krasnoyarsk pillars made of pink syenite “grew” on the body of a huge monolith. Many millions of years ago, during violent magmatic activity, molten magma was able to break through cracks in it and froze on the surface, forming a magical picture.

Syenite cannot be classified as a precious stone. It is not used in expensive jewelry. But its value lies elsewhere: it was and will remain a symbol of the eternity and inviolability of Nature, reminiscent of the fragility and insecurity of man.

Volcanic basalt (volcanite) (20 kg.) stones for baths and saunas.

The main differences between volcanic basalt and sauna stove stones from other stones used in saunas and baths:

- black color

- strong and durable. Service life more than 1000 cycles (3 times longer than gabbro-diabase, 10 times longer than crimson quartzite)

- not afraid of contact with open fire

- inert, has a stable mineral structure to destruction under the influence of high temperatures and water

– does not emit sulfur when heated and sprayed with water

- more environmentally friendly and safe for human health

- has unique bactericidal properties

- healing, at high temperatures it releases beneficial radiant energy, which increases metabolism, stimulates male potency, promotes rejuvenation and improves mood

- has high heat capacity and thermal conductivity.

Bath stone volcanic basalt is formed when erupted lava solidifies on the surface of the Earth, a melt of the main volcanic composition. Therefore, answering the question of which stones are best for a bathhouse, we can confidently answer that it is volcanic basalt. The origin of magma from volcanic basalt, according to one version, is a natural process of the earth’s crust when rock melts. Bath stone volcanic basalt is a very heat-intensive stone for baths and saunas.

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The hardness on the Mohs scale (this scale is used to evaluate the strength of stones) of volcanic basalt is 8. For comparison, the hardness on the Mohs scale for soapstone chloride is only 2-3, for Porphyrite only 6, for gabbro-diabase only 6, jadeite – 6.5-7. Stones that have a Mohs score greater than 7 are strong stones. If the coefficient is below 7, then such stones are not suitable for stoves, baths and saunas. Thus, answering the question of which stone to buy for a bath, or which stones to choose for a bath, we can confidently answer that basalt is the most durable stone for baths and saunas.

If we compare volcanic basalt according to the generally accepted coefficient of rock strength (M.M. Protodyakonov Scale), then basalt has the highest coefficient - 20 (the strongest rock). For comparison, soap chloride has only 8, while porphyrite has 15.

The ability of a stone for a bath and sauna stove to retain heat for a very long time is an important quality of a stone for a bath - its heat capacity. A bath stone should heat up quickly and retain heat for a long time

Volcanic basalt has a specific heat capacity (kJ/kg*C) of 1.1. For comparison, jadeite has a heat capacity coefficient of 0.88. Gabbro-diabase is about 0.7. Porphyrite about 0.85. Thus, volcanic basalt is the most heat-intensive stone for stoves, baths and saunas, which can be bought in Moscow and in the regions

A sauna stone should heat up quickly and retain heat for a long time. Volcanic basalt has a specific heat capacity (kJ/kg*C) of 1.1. For comparison, jadeite has a heat capacity coefficient of 0.88. Gabbro-diabase is about 0.7. Porphyrite about 0.85. Thus, volcanic basalt is the most heat-intensive stone for stoves, baths and saunas, which can be bought in Moscow and in the regions.

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When used in a stove, bath stones are subjected to heavy loads: first they are heated to a high temperature in a steam room, then they are filled with water from a ladle, the stone begins to cool unevenly. Not every stove stone can withstand such loads. Therefore, many bath stones lose their original appearance and need to be changed frequently. The higher the heat resistance of a bath stone, the longer the stone will last in the stove. The melting point of volcanic basalt is 1450 degrees. For comparison, jadeite has 1040 degrees. If we compare the number of heat resistance cycles. This is how many times the stone is heated and cooled, then volcanic basalt can withstand more than 1000 cycles. For comparison, gabbro-diabase - 300 cycles, crimson quartzite - 100, jadeite - 400, soapstone chloride - 500, porphyrite - 400. Thus, volcanic basalt is a very heat-resistant stone for bathhouse and sauna stoves and can be recommended to those people who are looking for an answer to the question which stones are best to choose for a bath.

We will be glad if you contact us and you will make sure that this is not in vain.

There are no analogues to this stone in the Russian Federation.

Bath stones.

Wholesale prices from 2 tons (100 kor) - check the price with the manager.

When quantity is important

The role of stones in a steam room largely depends on its type and model of heater. For small electric heaters weighing 10-20 kg, stones are needed not for steam generation, but to protect heating elements from overheating and people from hard infrared radiation from metal. With such a volume, even heat-intensive stones will only smooth out temperature fluctuations, but will not be able to accumulate much heat.

As the volume of the heater increases, careful selection of stones plays an increasingly important role. The general rule is: the more stones in the stove, the longer they will maintain the temperature in the steam room and the more high-quality steam you can get from them. Moreover, by changing the type of stones, you can significantly change the characteristics of the heater itself. For example, for a 200kg stove, jade can provide additional hours of steaming after the fire goes out compared to quartz.

Therefore, try to choose a larger stove and always completely fill the entire volume of the heater with stones. Of course, if you like a Russian bath, and not a Finnish dry-heat sauna.

What kind of water to pour on the stones in the bathhouse

IMPORTANT! The hotter the water, the smaller the temperature difference for the stones, which means there will be less wear and tear on them, and you won’t have to waste extra firewood. One big benefit!

Fill up with hot water in advance and place it near the heater so it doesn’t get cold

Fill up some hot water in advance and place it near the heater so it doesn’t get cold.

There are many recipes. The main thing is that all these additives do not simply burn out on overheated stones. Therefore, a special place is usually allocated for such a donation. Or, as an option, they simply place a container with pleasant-smelling contents next to the heater.

Gabbro for steam baths

Medicinal properties

The beneficial properties of dunite for use in a bath are based on the presence of olivine in it (of which dunite contains much more than in another widely used bath stone - dolerite), which has pronounced medicinal properties.

Bath procedures with dunite:

• normalize cardiac activity;
• reduce blood pressure;
• increase immunity;
• strengthen the nervous system;
• help with colds;
• used for eye diseases;
• used for diseases of the musculoskeletal system;
• disinfect problem skin;
• increase libido in men.

Specialists from the Institute of Mineralogy of the Ural Branch of the Russian Academy of Sciences gave the highest rating to dunite as a stone for use in baths and saunas.

Dunite is a natural air purifier that has a unique property: when heated in a bathhouse, this stone reacts with carbon dioxide and, thus, purifies the atmosphere in the room, eliminating the appearance of foreign odors.

Soapstone chlorite

When heated, soapstone emits soft, comfortable warmth

This rock has a denser and more durable structure than diabase. Externally, soapstone bath stones are discreet, but interesting and have a variety of shades of gray.

The rock has good heat capacity and resistance to chemically aggressive environments.

The most important advantage of the stone is that it heats up extremely quickly. It accumulates 2.5 times more heat than a stove brick and releases it evenly and for a long time. This means that soapstone generates “light” steam.

Among the beneficial properties of the rock, it can be noted that when heated, it emits soft and comfortable heat, in the infrared spectrum, similar to the sun. It increases our immunity and normalizes metabolism.

When choosing which stones are suitable for a bathhouse, keep in mind that soapstone may generate dust. You will get rid of this drawback if you rinse and heat the stones before the first bath procedure.

What is granite

Translated from Latin - grain. Natural granite is formed in nature over millions of years. There are 2 known types of origin of the stone:

1. Volcanic. The frozen lava of a volcano cools down and acquires a rocky structure. Over many years, granite stone crystallizes in it in the form of grains of different sizes. The process of turning sand into granite takes place along the same path.
2. Granitization. During the tectonic displacement of continental plates, different rocks moved deeper into the earth. High temperatures and pressures coupled with chemicals caused granitization.

It contains rocks:

• potassium feldspar;
• quartz;
• mica;
• acidic plagioclase;
• amphibole.

Sometimes additional components are found (pyroxene, graphite, talc and others).

In percentage terms, granite consists of minerals:

• 60–65% – feldspars;
• 25–30% – quartz;
• 5–10% – dark flowers.

It has a crystalline granular structure with crystals of large (more than 5 mm), medium (up to 2–5 mm) and small (up to 2 mm) sizes. There may be small empty cavities inside the stone (microlite granite) or cavities filled with other minerals (cellular or drusy granite).

Chemical composition

Chemical theoretical composition: MgO - 69.12; H2O - 30.88; Mn and Fe partially replace Mg; When Mg is replaced by Mn, no distortion occurs in the structure. In small quantities, Mg is also replaced by Zn (3.67% ZnO in manganbrucite from Franklin). Sometimes CO2 content is noted, which is apparently due to the presence of carbonate impurities. In brucite from the chromite-bearing massif of Southern Iraq (Bashkiria), Ga (0.0003%) was spectroscopically identified.

Varieties

Nemalite - nemalite - fine-fibrous. The name comes from the Greek “nema” - thread (Natel, 1821). Synonym of Nematolite - nematolite (Hinze, 1915). The fibers are elongated in parallel (0001). There are two types of nemalite: 1 - the direction of fiber elongation completely coincides with the a-axis (nemalite from Asbestos and Luoyang); 2 - the direction of elongation forms an arbitrary angle with a (nemalit from Lancaster and Hoboken counties). Colors are white, cream, emerald green, teal and black. The luster is glassy or silky. Elongation (—). Usually biaxial. The composition corresponds to the formula of brucite. Fersman distinguished between nemalite and ferronemalite - ferronemalite - with a FeO content of 5-7%.

Nemalit

Ferrobrusite - ferrobrucite (Lacroix, 1909) contains a significant amount of Fea+, replacing Mg (up to 36% FeO, according to Betekhtin). In appearance, in a fresh state, it is completely similar to brucite. In the light it turns brown and splits along cleavage planes. In the weathering zone it acquires a golden-brown color and turns into pyroaurite. It was observed in association with brucite (in zonal intergrowths) and with magnesium hydrocarbonates in cracks among highly serpentinized dunite, sometimes in chromite bodies. Iron-rich varieties were found in Russia in the Urals in platinum-bearing chromite deposits in the Nizhne Tagil dunite massif (according to Betekhtin, 1950). It is possible that collingite or its mixtures are sometimes mistaken for ferrobrusite.

Manganbrucite - manganbrucite (Igelström, 1882) contains a significant amount of Mn2+, replacing Mg. Synonym for manganobrucite. The mineral from Franklin has a ne of 1.60; no = 1.59. In air it quickly turns brown and black. Found in association with hausmannite and other minerals in manganese ores of Jacobsberg (Värmland, Sweden) and zinc ores of Franklin (New Jersey, USA).

Trigonal syngony.

Class. Ditrigonal-scalenohedral D3d - 3m (L33L23PC).

Crystal structure

The structure is layered, similar to the structure of CdJ2; the role of an anion is played by the (OH)1- group with an ion radius of 1.33 A. Such groups are arranged according to the principle of the closest hexagonal packing. Each layer consists of two parallel (0001), flat sheets folded by groups (OH), and a layer of Mg atoms located between them, occupying all the octahedral voids between the sheets (OH); each Mg atom is located between six (OH), linking three (OH)1- of one sheet with three (OH)1- (rotated by 180°) of the other sheet. Perfect cleavage passes between triple layers, linked to each other by weak residual bonding forces.

Nemalit

Main forms:

What are the requirements for stones?

There are a number of requirements for the quality of minerals, ignorance of which can lead to undesirable consequences. Many natural materials contain harmful elements, which subsequently escape along with steam.

When selecting stones yourself, you should take into account the objects near which they were collected. When purchasing quality products in a store, the packaging indicates that it has passed radiation control.

The main criteria that stones for a sauna or bath must meet:

• heat resistance. The stones must withstand the temperature created in the steam room and not crack in the fire. To test a cobblestone, it should be heated and placed in cold water. A good quality stone will not crack or burst as a result;
• size and shape. They are selected depending on the type of stove. For a large wood-burning stove, large cobblestones with a diameter of 80 to 120 mm are suitable. When using small electric furnaces, you need to select smaller stones - with a diameter of approximately 50 mm. The shape of minerals can be different. Laying flat small stones is easier.
• heat capacity, which determines the ability to accumulate heat and generate heat. Stones that retain heat for a long time are heavier and have a dense, homogeneous structure.

In addition to the basic qualities that allow you to retain heat, the aesthetic side of the issue is of no small importance. Combinations of different minerals can harmonize with the overall interior of the steam room

Natural materials can be processed - sanded or rolled.

This gives the boulders a more rounded shape. Many stones look good in their original form. Complex combinations can be created. For example, shungite goes well with jadeite, basalt with white quartz or colored quartzite.

Which is better: diked or crushed stones?

Usually stones for a bath are either chipped or piled. And the difference between them is not only in appearance.

Breaking rock into small pieces is basic processing. Therefore, split stones are cheaper, but they have irregular shapes and sharp edges, which makes them difficult to place in the heater. On the other hand, due to the same irregular shape, crushed stones produce more steam, since their surface area is larger.

Boned stones undergo processing, due to which they become smooth and rounded. Such stones look more beautiful, they are easy to place in the oven, and due to their rounded shape they are well ventilated. In addition, during processing, the “weak” parts of the stones with fragile inclusions are cut off, so they last longer than chipped stones.

What to replace

Dunite can be replaced by members of the peridotite family, the most common of which is olivine. Pyroxenites, such as jadeite, are also perfect. Its disadvantage is the high price.

In the same price category as dunite are:

All of them are suitable for use in baths.

Advantages of dunite:

• the stone heats up quickly, releases and conducts heat evenly, and does not expand;
• has fire-resistant properties, can withstand temperatures up to 1200 C, so you don’t have to worry about cracking;
• does not emit odor when heated;
• helps restore the nervous and musculoskeletal systems, has a beneficial effect on the condition of the skin and hair;
• interacts with carbon dioxide, protecting you from poisoning.

Flaws:

• unpresentable appearance due to the limited color range from gray, gray-green to black;
• short service life, approximately 6 years;
• transformation from strong dunite to porous serpentine;
• some stones have large inclusions of sulfur, which, under the influence of temperature and humidity, is formed into hydrogen sulfide acid;
• a large number of fakes on the market;
• most often has a small size.

Porphyrite in a kiln: problems and tips

Unfortunately, many people think that a heater is a heater, but they forget that it comes in three types . And in each of them, any stone will behave differently. This is in addition to the fact that there are problem stones that you need to be able to sift out yourself.

For heater

Let's look at each of the three types.

For closed

A closed heater is a metal container that has a solid bottom that prevents stones from coming into contact with the fire. A closed heater has a door through which it is loaded with stones and where water is added. Plus there may be a device for supplying water to the lower layers of the stone.

Porphyrite close-up. Photo Camelot178

A closed heater is designed to produce light steam in a Russian bath. This means that the temperature to which the stone is heated should be around 400 degrees. These are not the most comfortable conditions for a stone that you sharply cool with water at a temperature of 80-100 degrees. However, there is evidence from users that porphyrite works quietly in a closed heater for at least 2-3 years . Of course, you can’t call him a long-liver, but he will get his money’s worth.

For open

An open heater is not designed to produce light steam. The upper stones in it do not heat up above 100 degrees at all. Therefore, the steam from it is heavy, like water boiling on a stove. It's hard for them to breathe.

Open heaters are good in a sauna, where they add very little heat, just to slightly humidify the overheated air.

Stones in open heaters feel great, nothing threatens their existence, so they can lie there for years without changes. This applies to any stones, but also to porphyrite in particular.

For flow (direct heating)

There are batch stoves in which the heater is freely washed by the fire of the stove . To start steaming with such a stove, you need to turn off the fire. Only then can you apply water to the stones.

A flow-through heater is akin to a grate on which stones are laid. During operation of the furnace, they become very hot, until they glow brightly . Both this temperature regime and cooling even with boiling water is extreme for them.

Porphyrite fractions. Photo Camelot178

Therefore, not a single stone lasts long in direct-heated heaters. Let’s say that fibrous jade could still live as in a closed one, but all other stones begin to deteriorate more actively than in a closed one.

Owners of direct heating heaters need to either invest in stainless steel or be prepared to change stones frequently.

Those of them who have chosen porphyrite will have to change it quite quickly. Please note: we do not have exact information, but we believe that it will last no more than a year. Although this also depends on the number of fireboxes and the size of the stove. One thing is certain: when sand starts pouring out of it, you will notice it when cleaning the stove.

Life time

Well, from the above, everyone can imagine for themselves what the service life of porphyrite will be in their bathhouse. On average, 2-3 years in a closed one, in an open one - much longer, in a flow-through one - two times less than in a closed one.

How to choose

Now we will move on to specifics. People face certain problems when they buy, say, Karelian stone.

There is strong smoke from these stones in the steam room

Strong smoke is evidence that some substance is burning out in the stone. Of course, it should be clarified that there cannot be a lot of fuel in the stone, and here you also need to check whether the strong smoke is definitely from the stone or from problems with the stove or chimney?

But “strong smoke” can also be called a suffocating, eye-harming, unpleasant-smelling gas that appears after loading the heater with porphyrite. In this case, the owner was unlucky - he came across stones with an admixture of sulfides - sulfur compounds, which under the influence of high temperature are oxidized to sulfur oxides, which are themselves asphyxiating, and with water they form strong acids - sulfuric and sulfurous.

In this case, steaming should be stopped and the stove should not be turned off. If there are few sulfides, they will burn out on their own in a couple of idle heatings of the heater. But there can be many of them. In this case, you will have to sort out the heater or abandon the stone altogether.

Signs of sulfides are dark gray or brass-yellow spots or crystals on the surface of the stone with a metallic sheen. It's impossible to mix it up. If there are a lot of them, don’t buy such a stone. It’s not he who stinks, but these impurities.

Unfortunately, there are many complaints about Karelian stones that they often end up with sulfur impurities.

Explodes, snaps

The stone clicks is the sound of a tear inside the stone. tension accumulated in him which ended in a rupture.

Rocks that are already heavily fractured explode and crack. Masons call such a stone “old,” regardless of its type. It crumbles easily from light blows. It's better to check in advance.

Fractions of porphyrite stone. Photo Camelot178

The second option in which stones explode and crack is when they are composed of minerals with different thermal expansion . That is, one has expanded more, the other less, internal tension has arisen and it will subside if a crack or rupture forms. Therefore, it is not recommended to use granite in heaters .

Boned or chipped

The main difference between the two types of bath stones: bunded and chipped, is the amount of space left between the stones when laying. Space is needed for free penetration of water and hot air.

So, crushed stone gives a larger surface area of ​​the stone itself, and when laid, it gives greater density. But in a heater it is still preferable to leave a small space between the stones. And it appears naturally when you lay down rocks with rounded corners.

Dense laying is undesirable because it interferes with the thermal expansion of the stone, leading to stress and breakage.

In an open heater, the selection criterion may be the aesthetic preference of the owner.

Which faction is better

In terms of size for the heater, it is best to take stones in the range from 5 to 12 cm.

Later, divide them into three fractions: large, medium and small. For faster heating, it is better to lay the stones “upright” - so that the long side is vertical, leaving gaps, you need to start with large stones and move row by row to smaller ones.

How many do you need

The answer is obvious - focus on the quantity that is written in the stove's passport. Or calculate the volume of the heater using measurements and using reference data on the density of porphyrite, count the number of kilograms. In reality, of course, there will not be a complete filling, but some of the stones may be discarded, so you can take a little more.

Porphyrite fractions. Photo Camelot178

How to prepare

Preparing porphyrite for a bath comes down to checking it for the presence of sulfides, then for fracturing - to do this, put the stones in water and see if bubbles appear. If they appear, it is better not to put this stone in the stove.

Then you can do a crash test: heat the stones well and then throw them into the water. Whoever survives will live in the oven.

Stones should also be washed before laying. To do this, just rub them thoroughly with a stiff brush and rinse.

Laying: top or bottom

The question assumes that you have at least two types of stone, one of which is porphyrite. Well. If the second one is a more expensive stone, then place it on top and the porphyrite on the bottom.

In general, they put it down rather because it is a kind of “consumable”, that is, a fairly cheap stone that is sent to the most severe conditions, agreeing to frequent replacement, of course.

In a flow-through heater (ideally), it is best to place stainless steel down. There will be less work sorting out stones. Even one layer of stainless steel will extend the life of all the stones above it. But she's expensive. Therefore, the second option is to put down what is less pathetic. Porfirit is not very sorry. If there is gabbro-diabase, go down.

How often should you clean your heater?

It is recommended to clear the heater of stones at least once a year. If “shots” are often heard, then this is a reason for an unscheduled inspection.

In a flow-through heater there is also the problem coking , so it should be monitored more carefully and cleaned strictly periodically.

What kind of mineral is this?

The mineral got its name from the ancient Greek words “amphibolos” - “obscure” and “lithos” - “stone”. In appearance, amphibolite resembles granite, but in terms of artistic potential it is much superior to it.

Having a medium-grained structure, amphibolites can have an even color, ranging from grayish-green, black-green, brown, reddish and even blue.

The most decorative are the variegated varieties, which have a pronounced layering of mineral inclusions.

Colored or gray chips of amphibole and plagioclase, interspersed with layers of milky-white quartz, give products made from this stone a special expressiveness.

Where is it used?

The scope of its application is quite diverse. One of the most widespread applications is tombstones and monuments.

Dolerite is an excellent building material. For example, slabs are made from it, which are used to cover large surfaces - city squares, sidewalk paths, and other solid stone products. Due to the high wear resistance of stone, such roads do not lose their original appearance for decades.

In addition, diabase has proven itself well as a finishing material, both external and internal. For these purposes, polished slabs are used. They make excellent countertops, window sills, railings and stair steps.

The most famous objects made from dolerite are the Vorontsov Palace in Alupka (Crimea), the English castle Stonehenge, and Red Square in Moscow.

This breed has also found application in high-precision mechanical engineering. Small polished tiles for machine tools are made from it.

Diabase is also actively used in the jewelry industry as separate components or as an independent product.

In addition, dolerite is included in the group of stones suitable for baths.

Physicochemical characteristics

Dunite is characterized by a holocrystalline fine- or medium-grained structure, as well as a massive rock texture and high density. It is a mixture of olivine (up to 90%) with pyroxenes, amphibole and chromite. This rock is also extremely rich in magnesium and contains very small amounts of silica.

Average chemical composition:

• SiO2 35-40%,
• MgO 38-50%,
• FeO 3-6%,
• Al2O3 up to 2.5%,
• CaO up to 1.5%,
• Fe2O3 0.5-7%,
• Na2O up to 0.3%,
• K2O up to 0.25%,
• TiO2 up to 0.02%.