How many calories in pomegranate, nutritional value, composition. Useful properties of pomegranate, harm and contraindications

The healing qualities of pomegranate are determined by the vitamins and other healthy and useful components included in its composition. Medicinal characteristics have both grains and peel, branches, foliage and tree bark.

And yet the main value is juicy grains, from which a wonderful juice comes out, practiced successfully and with benefits for restoring strength in the postoperative period and after infectious diseases.

What else is pomegranate useful for?

1. The bark of the tree stores tannins that have disinfecting properties. After conducting scientific experiments, it was found that the useful elements that are in the composition of the bark are a strong drug against intestinal, tuberculosis and dysentery bacilli.
2. An aqueous infusion of the bark is used as a galenic antiseptic in case of an infection;
3. Contained in pomegranate seeds fixed oils, contribute to the normalization hormonal balance, in addition, lower blood pressure, repay nervousness and relieve headaches.
4. The benefits of pomegranate for the body also lie in 15 amino acids, 50% of which are found only in meat products and represent a certain significance for the body.
5. A powder with astringent characteristics is made from the bark of the tree, used for the treatment of enterocolitis. Decoction strengthens the gums, heals the kidneys, liver and is used for various fractures;
6. In addition, at enhanced action on the skin of ultraviolet radiation, in fact healing qualities juice and help preserve the elasticity and softness of the skin. Pomegranate juice will keep the skin soft and velvety for a long time.
7. Among other things, the benefits of pomegranates for the body and in anti-cancer characteristics. Experts say that the value of the fruit and the juice from it lies in the fact that when taken systematically, the risk of breast cancer in women is significantly reduced.

After the x-ray examination, eat a pomegranate to eliminate all possible effects of radioactive effects on the health of the body.

Pomegranate - for expectant mothers

Pomegranate is also recommended for pregnant women, since it contains oxytocin, i.e., a hormone that reduces pain. Currently, there are no drugs that would store this hormone in an easily digestible form, therefore, during this period, you must definitely use this fruit.

The pomegranate contains valuable elements that are of particular importance for the health of pregnant women. The fruit is replete with such a vitamin and mineral set that can significantly reduce toxicosis, produces hemoglobin and increases the iron content in the body. As a result of all of the above, pomegranate for the health of expectant mothers should become a priority fruit;

Pomegranate seeds benefits and harm to the body

In addition to a large assortment of vitamins and minerals, the bones also store fatty oils. As soon as they have remarkable property regulate the hormonal environment of the human body.

Grains, like the juice from this fruit, are good for health to use as food.

They extinguish nervousness, reduce headaches, normalize blood pressure, free the intestines from harmful and unnecessary elements.

Pomegranate seeds - for women

Pomegranate seeds will help streamline the beautiful sex menstrual cycle, reduce the negative symptoms of menopause, help improve health in postmenopausal times.

men

For a strong sex, the bones of this fruit will help increase potency and improve sperm production.

Harm of pomegranate seeds

There is information that they are able to excite:

• Inflammatory processes and swelling of the gums (due to microtrauma);
• Suspension of regular stools and constipation.

The bones of the described fruit should not be given to young children, as well as to people with gastrointestinal diseases.

Pomegranate juice

Invigorating juice with a tart taste is a good opportunity to increase your appetite and streamline the activity of the digestive tract. In addition:

1. The juice from this fruit and a decoction of the peel can help with dysbacteriosis.
2. The drink contains as many antioxidants as green tea and has restorative and cleansing properties.
3. The juice contains enough elements that give it diuretic, anti-inflammatory, disinfecting and analgesic qualities.
4. Pomegranate juice helps increase hemoglobin and strengthen the body's immune system.
5. Juice is necessary for pregnant women, specially diluted with beet juice or carrot juice.
6. Pomegranate juice is prescribed for detected anemia or exhaustion, provoked by a long illness.

This wonderful fruit has been adored and revered since time immemorial. In ancient Greece, it was believed that nymphs lived on these trees, and pomegranate seeds were droplets of the blood of the god Dionysus.

In some nations, a beautiful fruit is identified with passion, fidelity of spouses, wealth and fertility. Chroniclers claim that the fruit of the pomegranate became the prototype of the royal crown.

Back in ancient times, the famous ancient Greek Aesculapius and mentor Hippocrates, told about medicinal properties pomegranate and prescribed juice for the treatment of disorders and diseases of the skin. Ever since those ancient years, people have known how useful the fruits of this tree are.

Harm and contraindications when using pomegranates

Along with the rare valuable properties and benefits of pomegranate, there are also separate prohibitions and restrictions that you need to know about.

1. Presence in fetus a large number different acids, can cause very significant damage to human health in the absence of the necessary information.
2. With caution, it is necessary to eat pomegranate with increased sensitivity of tooth enamel, since the acids in its content are extremely harmful to teeth.
3. Nursing mothers are forbidden to use pomegranate or juice from it, in order to avoid dyspepsia or allergies in the child.
4. You can not use pomegranate, people suffering from gastritis, pancreatitis, gastrointestinal ulcers, because a large presence of acid will adversely affect the well-being of the mucous surface.
5. Pomegranate juice has a significant concentration useful elements, as a result, with the existing contraindications, it is not recommended to use it undiluted.

Pomegranate with white grains

Pomegranate, with almost white grains, is called "Tuya tish", in translation - "Camel's tooth". The grains are large, but still not pure white. This variety has a sweet delicate taste and aroma.
White pomegranate has valuable characteristics similar to red fruit.

vitamins in pomegranate

The pomegranate contains:

Pomegranate peel benefits and harms

In a pomegranate useful qualities much more than in juice and red grains. In its composition, the peel stores enough vitamins and minerals.

• Pomegranate peel undoubtedly benefits the body:
• The useful composition of the pomegranate peel is used for hypotension, seasonal colds and infections;
• The general strengthening characteristics of the pomegranate peel are used when there is a lack of iodine, potassium and iron in the body;
• Tannins in the peel will reduce and eliminate signs of inflammation;
• The catechins, polyphenols and bioflavonoids stored in the peel of the fruit have an antimicrobial and antioxidant effect;
• Tinctures made on the peel of the fetus can cure ulcers and other inflammations in the gastrointestinal tract, diarrhea, reduced coagulation, intestinal infections and dental diseases;
• The peel also has an effect when used as a preventive measure for diseases of the heart and blood vessels;
• Lotions made from a decoction of fruit peels will help the healing process of minor wounds and sores;
• Powder from dried fruit peels is used to eliminate cracks and wounds on the skin;
• Pomegranate peel is able to rid the body of worms;
• It will help with bleeding gums - you should systematically rinse your mouth with an infusion of pomegranate peels;

Harm of pomegranate peel

The beneficial characteristics of fruit peels are much greater than the likely harm of their use, but there are side effects and they cannot be ignored.

1. The peel of the fruit should not be used by persons allergic to this fruit.
2. Pomegranate peels are not advised to be used to treat diseases of the liver and kidneys.
3. Not recommended for use pomegranate peel without prior consultation with a specialist;

History of the pomegranate

History of pomegranate This fruit was known about four millennia ago, Tunisia and Asia Minor are considered to be its cradle, from where it moved to the subtropical and tropical regions of the planet. The pomegranate was a symbol of fertility.

In the East, pomegranate is called the king of fruits. The valuable qualities of the red fruit have been glorified since ancient times. The ancient Greeks were convinced that a grenade could kindle love and keep the body in excellent condition.

At present, science has proven that this worthy fruit strengthens the immune system and supports the body in the fight against various diseases.

This excellent apple-sized fruit grows in the regions of the East and the Mediterranean. From above it is shrouded in a hard burgundy peel, and inside it there are many red saturated grains.

Pomegranate contains so many necessary and healthy substances which can fully provide the human body with all the necessary elements for its proper functioning.

The vitamins and minerals stored in it help to strengthen the immune system and blood vessels, promote normal hematopoiesis and strengthen the central nervous system.

Video: 10 reasons to eat pomegranate

Pomegranate is called the king of fruits, this is due to the fact that the fruits of the plant contain many vitamins, minerals and substances, the benefits of which for the human body are undeniable. But it is worth noting that the use of pomegranate can be not only beneficial, but also harmful to health, since the concentration of some substances in it is high and drinking juice in its pure form can damage the gastrointestinal tract. Therefore, it is important to familiarize yourself with the beneficial properties and contraindications for eating the fruit, which are given in this article, we will also consider the topic “Pomegranate health benefits and harms”. Full information will help you use the benefits of pomegranate most effectively.

What is useful pomegranate

The benefits of pomegranate for the body are obvious, due to the fact that the fruit has a high content of various vitamins. The unique composition of the product provides positive influence to the central nervous system, helps in the fight against excess weight, carries protective function from many infectious diseases, improves the general physical condition of the body.

At diet food pomegranate is also useful, the nutritional value of which is high, and the average product is only 60 kcal per 100 grams of fruit, and 50 kcal per 100 grams of juice. And to prepare a therapeutic soothing tea, you just need to dry and grind the pomegranate partitions, then add them to a hot drink.

Thus, we found out that pomegranate is useful for the human body in the form of grains, juice, infusions from the peel and partitions. Grains can be consumed fresh, as part of dishes, such as salads; juice is also used in its pure form, or diluted with water, to reduce aggressive concentrated components; and the peel of the fruit and its partitions are excellent for making drinks, with health problems.

Medicinal properties of pomegranate

From the pomegranate are obtained medicinal drinks, which you can cook at home tasty and fast. For example, to make a stress-relieving tea, you need to drain and grind the peel and partitions of a pomegranate and add a teaspoon of the resulting mass to a cup of your favorite drink. Medicinal properties pomegranate has been known for a long time, these fruits have a lot of useful qualities and are actively used in traditional medicine, home beauty recipes and cosmetology. The use of pomegranate is recommended for the treatment and prevention of the following diseases:

• Poisoning, stool disorder, diarrhea;
• Blood pressure disorders;
• Thyroid diseases;
• Exhaustion, reduced immunity;
• Bronchial asthma;
• The fruit is useful for anemia and anemia.

Pomegranate promotes weight loss and the breakdown of body fat, it is widely used in the preparation of a diet for people who want to lose weight. Due to the high concentration of active substances, the fruit has a general tonic and firming effect.

The benefits of eating fruits are especially high for the elderly, thanks to special acids and vitamins, pomegranate can be used as a good tool to strengthen the walls of blood vessels.

Useful properties of pomegranate peel

Pomegranate peel contains isopelletierins, alkaloids and pseudopelletierins, which play an important role in the treatment of many diseases, for example, pseudopelletierins are a good remedy from worms, and a decoction of the peel is popular for inflammation in the joints and organs, as it has an excellent anti-inflammatory effect.

10 reasons to eat pomegranate:

1. The fruit is tasty and useful assistant in the fight against excess weight;
2. Other fruits contain less vitamins;
3. With irregular nutrition, the use of pomegranate is to normalize metabolic processes in the body;
4. Eating a healthy fruit normalizes digestion and relieves diarrhea;
5. The fruit has a disinfectant effect on the mouth and throat area, which prevents diseases oral cavity and some cold infections;
6. Pomegranate increases hemoglobin and perfectly fights anemia and anemia. Pomegranate is of particular benefit for anemia, because eating it increases hemoglobin and strengthens the walls of blood vessels, relieves inflammation. Pomegranate for human blood is beneficial, improves and normalizes its composition;
7. Sweet ;
8. If this ripe fruit is present in the human diet, he will not be afraid of viral infections;
9. The use of grains in food has a beneficial effect on conditions skin, and if you make a mask from the peel, you can even overcome purulent rashes;
10. Pomegranate reduces blood pressure and shows anti-inflammatory effect.

But eating this fruit or drinking pure juice is not recommended, especially in unreasonable quantities, it is worth observing correct dosage or dilute the juice with water to reduce the concentration of active substances that can be detrimental to health. The benefits and harms of pomegranate directly depend on the amount and method of its consumption.

Chemical composition

The overall chemical composition of the fruit is very rich, because it includes a lot of vitamins, calcium, fiber, magnesium, potassium, sodium and manganese. Iron in a pomegranate is contained in a small amount, only 1 mg per 100 g of the product, but eating the fruit increases the iron content in the human body. Bzhu indicators in 1 pomegranate, weighing 200-250 gr: proteins - 18 gr; fats - 0 gr; carbohydrates - 25 gr.

What vitamins are in pomegranate

Consider what vitamins pomegranates contain and why they are useful:

• Vitamin C. Vitamin strengthens the immune system, helps the body resist various diseases;
• Vitamin B6. B6 has a positive effect on the nervous system, increases its functionality and normalizes the work of the central nervous system;
• Vitamin B12. This vitamin is essential for hematopoiesis;
• Vitamin R. Strengthens the walls of blood vessels.

How many calories are in a pomegranate

The calorie content of a pomegranate with seeds depends on the sweetness and composition of a particular fruit, but the average value is 60 kcal per 100 g of product. The pitted pomegranate has a slightly lower calorie content, about 50 kcal per 100 g of product.

The fruit is rightfully considered dietary and low-calorie; there is no fat in the composition of the product. Therefore, it is easy to digest and does not leave any deposits under the skin, moreover, active substances, which are part of the fetus, break down fats in the body.

What are useful grenades for women

The benefits of pomegranate for women are concentrated in its unique composition, rich in vitamins and trace elements. Another pomegranate is useful during menopause and hormonal disruptions, the fruit improves psychological condition the fair sex and normalizes hormonal background. Pomegranate is useful for women who are at risk of breast diseases, the high content of ellagitannin prevents cancer.

It is recommended to drink pomegranate juice, but always diluted with water, so as not to damage inner surface stomach. The drink relieves puffiness, attacks of nausea during toxicosis, has a beneficial effect on the state of the blood and nervous system of the expectant mother, and the juice is also a good diuretic and perfectly quenches thirst.

Benefits of pomegranate for men

The benefit of pomegranate for men is vitamin B12, it improves erection. Also, red and yellow fruits are useful for the body of a man, these products contain vitamins, microelements and a high content of active substances.

Juice and infusions from the peel strengthen the male body, fill it with strength, quench thirst and are an excellent source of energy and tone. To achieve the maximum positive effect, you must use the product regularly.

pomegranate treatment

Useful fruit is widely used as a component of the remedy home remedy for the stomach, skin, treatment of anemia and getting rid of worms. It helps with inflammatory processes in the body, calms the nervous system and lowers blood pressure. In folk medicine, there are many variations of recipes for pomegranate treatment.

The extract of this useful plant and its fruits is part of some medical and cosmetic preparations. Drinks made from fruit grains are widespread, they have beneficial effect on the human body, saturate with essential vitamins.

What is harmful pomegranate

The harm of pomegranate is that a strong concentration of substances can have an aggressive effect on the stomach, mucous membranes and the body as a whole, therefore it is recommended to drink diluted juice and not eat the fruit on an empty stomach.

Contraindications to the use of pomegranate:

• Acute stage of pancreatitis;
• peptic ulcer gastrointestinal tract;
• Gastritis with high acidity;
• constipation;
• Individual intolerance;
• Allergy;
• Diseases of teeth and enamel.

When in doubt, it is better to consult a doctor and clarify whether pomegranate is harmful in your specific case. Also, do not give fruit and juice to children under one year old. Among those who should not eat this product, people who have chronic diseases, capable of aggravating due to the components of the pomegranate.

Useful properties of pomegranate juice

Pomegranate is one of the most unusual and mysterious fruits. In ancient times, due to its unusual shape and sweet and sour taste, it was believed that it was of divine origin. Perhaps due to the large number of seeds in some countries, pomegranate is considered a symbol of fertility, cordial affection and friendship. In this article, we will look at the calorie content, nutritional value and composition of the fruit.

In our country, pomegranate appeared relatively recently, but quickly gained popularity and universal love. It's not just about taste, it's also about health benefits.

The composition of the pomegranate

The edible part of the fruit is about 2/3 of the fruit, and the rest is the peel. The calorie content of peeled pomegranate is relatively low, but more on that below. The pulp consists of:

• sucrose, fructose and glucose - from 10 to 20%;
• fiber - 0.3-5.5%;
• tannins - about 1.2%;
• ash - up to 0.8%;
• various acids (citric, tartaric, etc.) - from 0.5 to 6%;
• vitamins and minerals - about 0.3%;
• all the rest is water and BJU.

pomegranate calories

The calorie content of one pomegranate is a loose concept, since a fruit can have different sizes- from 100 grams to a kilogram. In this regard, it is better to estimate the calorie content of pomegranate per 100 g:

• in the pulp - 80 kcal;
• in juice - about 50 kcal;
• calorie pomegranate with seeds - about 90 kcal.

Medium calorie fruit, low in saturated fat. There is no cholesterol in it, a lot of potassium and a minimum of sodium, and it also contains a lot of ascorbic acid. Many people wonder if pomegranate is an acidic or alkaline fruit. Experts classify it as a medium-sour food, keep this in mind if you have stomach problems.

We figured out the calorie content of fresh pomegranate, and now consider the concentration of BJU per 100 g:

• proteins - 0.9 g;
• fat - 0;
• carbohydrates - up to 14 g.

Nutritional value of the product

The nutritional value of pomegranate in 100 g is low. The fruit contains approximately 5 percent fiber and 15 different amino acids, for example:

• lysine;
• cystine;
• hydroxyproline;
• histidine;
• aspartic acid;
• glutamine;
• serine;
• arginine.

Some of them are indispensable and are contained in certain medicines. Pomegranate also contains a lot of vitamins and minerals, which you can read more about in a separate article.

Due to the low calorie content of pomegranate without peel and the high content of amino acids, the fruit helps the cells of the body to synthesize protein. It is needed for the construction of skin cells, blood and all tissues in the body, and it is also needed for the normal flow of material metabolism and hormonal processes.

The pomegranate is a fruit that has spread throughout the world from the area South-East Asia. Its scientific name is Punica Granatum. This is a seasonal fruit that is best eaten during the autumn months, as it is at this time that it has the maximum taste and benefits for the body. However, there are not only the beneficial properties of the pomegranate fruit, but also some contraindications from its excessive consumption.

The pomegranate is a fleshy fruit of the pomegranate tree that is native to tropical and subtropical regions. It is spherical and slightly larger than an apple. Thick dark red skin color protects the inner contents of the fetus, which contains many red seeds or seeds separated by membrane partitions. Each seed is located inside a liquid-like substance, therefore it resembles a small berry in shape. This liquid has a bittersweet taste.

As the fruit ripens, the peel bursts, and the seeds show up. There are types of pomegranate, the fruit of which is smaller and does not contain seeds inside.

According to historical sources, the fruit originates from Persia. From here, in ancient times, Phoenician navigators brought it to the western zones of the Mediterranean Sea, and soon Carthage became the main producer and exporter of pomegranate. In parallel, this fruit was cultivated in Ancient Egypt in the second millennium BC. Juice was made from its fruits, which was highly valued. Arabs brought pomegranate to Spain, from where he came to the American continent after its European colonization.

The loosestrife family consists of two species: punica garnetum or ordinary pomegranate, which is known throughout the world, and punica protopunica, which is grown in southern Yemen. The common pomegranate exists in various variations: a dwarf fruit growing on shrubs with small, narrow leaves and small flowers; large fruits with double yellow, white or red flowers; royal pomegranate and other varieties.

The chemical composition of the fruit

The pomegranate is made up of many chemical substances that have biological value. Moreover, these substances are various parts fruit: peel, membranes, seeds, juice. Juice is the most important product fetus, as well as the most studied in comparison with other parts of it.

About 50% of the weight of the fruit is in the peel and membranes, which are important sources of bioactive compounds (polyphenols, flavonoids, elagotannins) and essential minerals (potassium, nitrogen, calcium, phosphorus, magnesium and sodium). The edible part of the fruit makes up the other 50% by weight, of which 80% is the juicy mass and 20% is the seeds.

Chemical composition pomegranate seeds:

• water (85%);
• sugar (10%) is mainly fructose and glucose;
• organic acids (1.5%), these include ascorbic, citrus and malic acids;
• bioactive components such as polyphenols, flavonoids (anthocyanin).

In addition, the grains of this fruit are a source of important lipids for the body, since they contain fatty acids in an amount of 12 to 20% of dry weight. The variety of fatty acids is characterized by a large content unsaturated acids : linoleic and linolenic, punic, oleic and palmitic.

Benefits for the human body

The nutritional value of the pomegranate is noted in all religious sources, including the Bible. Throughout history, this fruit has been considered a symbol of prosperity and fertility. Pomegranate is rich in carbohydrates, important B vitamins (B1, B2, B3, B6 and B9), vitamin C, minerals (calcium, potassium, magnesium, iron) and other beneficial substances.

The fruit retains its nutritional value for several days at temperatures environment. Thanks to the tannins it contains, it has astringent and anti-inflammatory properties, which has favorable influence on the intestinal mucosa during intestinal colic or profuse gas emission. Thanks to citrus acid, pomegranate is a huge help in the withdrawal uric acid from the body, which is useful if a person suffers from hyperuricemia or gout. The flowers of the plant can be used to make tinctures against diarrhea.

The use of pomegranate is recommended due to the high content of antioxidants and antiseptics in it, which help to reduce the risk of diseases of the cardiovascular system. And since the fruit also contains potassium and not a large number of sodium, its use has a positive effect on people who suffer from hypertension.

Latest Research demonstrated that the fruit contains three times more antioxidants than green tea and red wine. These antioxidants play an important role in maintaining healthy condition circulatory system, preventing the formation of cholesterol plates in blood vessels by regulating arterial pressure and preventing premature aging cells and their oxidation.

The phytoestrogens contained in the pomegranate help maintain the health of a woman during menopause. The pomegranate fruit does not contain harmful substances for human health. saturated fat and cholesterol, while it is rich in plant fiber and vitamins C and K. Eating pomegranate along with other fruits and herbs is believed to prevent the development of certain types of cancer, including lung cancer.

Healing properties

Thanks to a whole range of beneficial chemicals, pomegranate has healing properties for various systems of the human body. The most important of these properties are the following:

Pomegranate Juice as Natural Viagra

Conducted at Queen Margaret University in Edinburgh (Scotland), a study revealed the following fact: every day drinking a glass of pomegranate juice equivalent to Viagra in its effect on erectile dysfunction men.

Researchers conducted several series of experiments with a group of volunteers aged 21 to 64 years and found that if you drink a glass of juice of this fruit every day for two weeks, then the level of testosterone in the blood increases by 30%. According to this study, sexual desire is increased not only in men, but also in women.

In addition, pomegranate juice increases the density of facial hair in men, and can also lower the timbre of their voices. In the case of women, it helps to strengthen the bones and muscles of the body.

Increasing testosterone levels has other positive effects, including improved memory, emotional state and decreased levels of the stress hormone (cortisol).

The same researchers have shown that the substances contained in pomegranate juice help in the fight against cancer, various disorders stomach, osteoarthritis and conjunctivitis.

Side effects of eating pomegranate

If we raise the issue of the benefits and harms of the pomegranate fruit, then we can say that it has many properties that are beneficial to human health, however, there are some contraindications when eating it for certain groups of people. These contraindications are well studied at present.

Diseases of the gastrointestinal tract and allergies

The most frequent side effects from this fruit are nausea, vomiting, abdominal pain and diarrhea. Such a pattern of symptoms occurs, as a rule, with excessive consumption of fruit juice and its seeds. All these problems of the gastrointestinal tract are not long-term and usually disappear in a couple of hours. Apart from excess pomegranate, such symptoms may appear due to its use with other incompatible products, these include products containing oils. Since the fruit contains astringents, it is not recommended to use it for constipation.

If a person is allergic to certain types of fruits, then he should be careful before eating pomegranate. Asthma sufferers should also avoid this fruit as it can cause an adverse reaction. An allergy from a pomegranate fruit can manifest itself in the form of a variety of symptoms:

• Pain and inflammation in the oral cavity;
• Pain while swallowing food or saliva;
• The appearance of hives and other types of rash;
• Difficulty breathing;
• Swelling of the face.

Blood pressure, enzymes and sugars

Pomegranate seeds reduce pressure in the blood vessels, so there are both benefits and harms of pomegranate for the body, that is, if a person has high pressure, then it is useful, if it is low, then its use should be avoided. It is also contraindicated to eat pomegranate for people who are undergoing any course of treatment for low or high blood pressure and take appropriate medications. Since the substances in the seeds of the fruit can reduce arterial pressure, they can interact with medicines and the consequences can be unpredictable.

Some scientific studies have observed the ability of pomegranate juice to reduce the effectiveness or completely inhibit the activity of certain enzymes secreted by the liver. Such enzymes are responsible for accelerating the decomposition reactions of chemicals, therefore, in the absence of such reactions toxic substances accumulate in the body, which can lead to its poisoning. Therefore, if you are taking any medication, then you should consult your doctor about what to eat and what to avoid.

Given that the fruit is rich in sugars and carbohydrates, people with diabetes should limit their consumption. Also, if a person is on a strict low calorie food diet, then this juice is not for them due to its average calorie content.

Keep in mind that this fruit contains a fairly strong red enzyme that can be difficult to remove if it gets on your clothes. Be careful when eating pomegranate.

Thus, the question of the benefits and contraindications of pomegranate fruit can be reduced to a simple conclusion: its excessive use can lead to various problems with health, and moderate consumption has a positive effect on the health of the body. So if you like the taste of this wonderful fruit, then include it in your diet in limited quantities and enjoy its positive effects.

Attention, only TODAY!

grenades- this is an extensive group of minerals (representing mixtures of two isomorphic series) with general formula R3R23, where R3= Ca, Mg, Mn, and R2= Al, Fe, Cr.

They usually occur in well-defined isometric crystals (rhombic dodecahedrons and tetragontrioctahedra or combinations thereof). Sometimes they form continuous granular masses.

Synonyms: Garnetite - garnetite. Venisa, garamantikus, worm, Yakut (Yagut) - old Russian names.
The names of garnets, which in composition occupy an intermediate position between the extreme members of the isomorphic series: ugrandite - ugrandite - between uvarovite, grossular and andradite; grandite - grandite - between grossular and andradite; mangagrandite, manganese grandite - mangan-grandite - between grossular and andradite, contains a small amount of manganese; pyralmandine - pyralmandine, pyralmandite; calcium pyralmandine - calc-pyralmandite - contains a small amount of calcium; pyrandine - pyrandine - between pyrope and almandine; pyralspite - pyralspite - between pyrope, almandine and spessartine; spandite - spandite - between spessartine and andradite (Fermor,. 1907); spalmandine - spalmandite - between spessartine and almandine; brandaosite - brandaosite, between spessartine and almandine, containing in addition Fe 3+ ; gralmandine - gralmandite - between grossular and almandine; magnesia-gralmandite - magnesia-gralmandite - contains increased amount magnesium; manganese gralmandine - manganese-gralmandite - contains a large amount of manganese.
The names proposed by Vinchel (ugrandite, pyralspit) have become widely accepted in petrographic practice.

origin of name

The name (garnet) is given by the similarity of the color of the originally studied stones with the color of the grains in the fruits of the pomegranate tree.

pomegranate formula

The described group includes minerals of the cubic system with the general formula A 3 B 2 (SiO 4 ) 3, where A is Ca, Mg, Fe 2+, Mn 2+; B - Al, Fe 3+, Cr, Ti, Mn 3+, V, Zr. They show a wide range of isomorphism.

Chemical composition

In these minerals, Mg and Fe 2+ , as well as Fe 2+ and Mn 2+ replace each other indefinitely. The isomorphism of Fe 3+ , Al, Cr, Ti, Mn 3+ , V, Y, Ce is widely manifested. Sometimes Si is replaced by Al, less often by Ti and Zr. Unlimited isomorphism of grossular and uvarovite, grossular and andradite, almandine and pyrope, almandine and spessartine, pyrope and spessartine, probably uvarovite and andradite molecules is characteristic. Intermediate members between pyralspits and grandites are rare. Complete miscibility of grossular with spessartine, grossular with almandine, or grossular with pyrope is possible only when favorable conditions, which sometimes occur in metamorphic complexes or during synthesis. Isomorphic mixtures of pyrope and spessartine are absent. Full miscibility of andradite and high-titanium shorlomite was noted. The most significant factor determining the existence of isomorphic mixtures in the garnet group is the size of the ionic radii of the cations. The gap in miscibility between spessartine and grossular can be explained by the difference in the size of the Mn 2+ and Ca 2+ ions, especially in the octal coordination. When studying zoned garnets by the electron microprobe method, differences were established in the content of Mg, Ca, Mn, Fe, Si in individual zones.

During crystallization, the mineral is capable of capturing He dissolved in magma. The earlier minerals contain more He; minerals from pegmatites contain no more than from skarns. Stones from Ungursay pegmatite veins contain 1.60 mm 3 He in 1 g of the substance. The mineral from the crystalline schists of Upper Svaneti contains 0.002% Li and 0.013% Rb; garnet from pegmatites of Kalba - 0.05% Rb. in grenades Eastern Siberia Be was found: from quartz-spodumene pegmatites - 0.0002-0.0003%, from quartz-albite - 0.0001-0.0008%; Sc is characteristic of garnets from shales (probably replaces Mg or Fe 2+ ), is found in garnets from syenites and pegmatites of the Elet’ozero massif in Karelia (0.0019-0.0027% Sc). In some minerals of the group, a small amount of Mn 3+ was found; Ga (0.0455%) is found in garnet from Kalba pegmatites, Ge (0.0029-0.0066%) - in hydrothermal garnet.
In essentially calcium garnets, Ca is replaced by strontium; Zn is found in garnets rich in Mn, Fe, Mg (replaces Fe 2+ ); Sn was determined in garnet from syenite of the Arga-Yuryakh intrusion in Yakutia (0.0184%), from the Myshikkol skarn-magnetite deposit in the Kurama Range (0.2%), and from quartz-micaceous hornfelses of Uzbekistan (0.13% SnO,).
For a stone containing a small amount of tin, an insufficiently substantiated name dhanrasite was proposed - dhanrasite (Marty, 1967).
The highest content of rare earths is characteristic of spessartine (spessartine from Kanozero on the Kola Peninsula contains 3.05% TR 2 O 3 ); characteristic is the presence of yttrium in spessartine (up to 2%), which is less common in essentially magnesian garnets. Andradite from granite pegmatites of Gatineau Park in Quebec (Canada) contains 0.75-2.65% Y. Almandine from Schreiberhau in the USA also stands out for its high content of rare earths (2.64% TR 2 O 3 ). Known grenades containing 0.001% Nb 2 O 8 ; 0.0004% Ti was found in the Sayan pegmatite garnet.

The content of uranium in them varies within 10 -8 -10 -5 g/m, its higher concentrations are typical for essentially calcium garnets confined to alkaline rocks. The impurity elements of some garnets include K, Na, P.
In minerals from granites, pegmatites, greisens, and quartz veins, the manganese component predominates, and Ti, Y, Sc, Ge, Ga, Be, Sn, and Zr are impurity elements. Skarns are most characterized by essentially calcium garnets; Impurity elements of such minerals are in sulfide skarns - Ti, Ge, Sn, As, Pb, Cu, V, in iron ore skarns - Ti, Cr, V, Ni, Co, Zr, Y, Sc. The same elements are found in garnets from amphibolites, gneisses, and metamorphosed basic rocks. Y, Sc, Ge, Ga, Be are common in spessartine-almandines, and Y, Cr, Ni, and Cu are common in grossular andradites.
According to Ford, one sixth of all analyzed garnets is composed of molecules of the two extreme members of the isomorphic series, i.e., two minals, and contains no more than 5% of other minals; one sixth contains four minals and the remaining two thirds three minals. Böcke has constructed diagrams showing isomorphism limits for various garnet end-members; the limits of isomorphic substitutions are indicated by him for groups of oxides; Herich gave similar data for each oxide separately. Ford constructed three-component diagrams that allow one to determine the composition of garnet from density and refractive index. Philipsborn concluded that to determine the composition of a garnet, it is necessary to know the density, refractive index and weight content (in%) of the divalent cation oxide (preferably Ca) or the density, refractive index and weight content (%) of the two divalent cation oxides. Stockwell pointed out an additive dependence between the composition and the size of the unit cell, which makes it possible to judge the predominant garnet component from the intensity of the powderogram lines. Fritsch noted the possibility of determining the composition of garnet from the size of the unit cell and the refractive index. Diagrams of the dependence of the refractive index and unit cell size on the composition were also proposed by other authors.

The chemical composition depends on the type of host rock. According to the ratio of the chemical composition of garnets and the nature of the host rocks, Tröger identified 28, and Sobolev 37 paragenetic types of garnets.
In the petrographic literature, to compare iron-bearing garnets, “iron content” is used - the ratio of FeO:FeO + MgO (in %). The most ferruginous garnets (75-79%) are found in the gneisses of Canada, the USA, and Finland. In the same rocks, the iron content of garnets can fluctuate. Thus, in gneiss garnets, it varies from 58 to 79%, which is associated with various conditions of formation, primarily with the pressure. The iron content of garnets increases from high-temperature ceramic pegmatites to lower-temperature rare-metal ones. Their iron content is interconnected with the iron content of coexisting minerals. The iron content of artificial garnets of the andradite - grossular series depends on the acidity - alkalinity of the medium; garnets with a high content of andradite component were obtained in alkaline environments, with a high content of the grossular component - in acidic environments.
In association with cordierite, garnet can be stable in a fairly wide range of iron content (20-25%) - within the almandine-pyrope composition. The study of the association of garnet with cordierite is important for determining the P-T conditions for the formation of metamorphic rocks and the depth of their formation. The compositions of garnet and cordierite associated with it are similar in many metamorphic provinces, which indicates similar conditions of metamorphism.
The composition of garnet and the concentration of certain elements in it depend on the association of minerals in which it is located.

Varieties of pomegranates

In nature, only intermediate members of isomorphic series occur; the extreme terms obtained artificially are distinguished under the following names:

1) Aluminum:

Pyrope Mg 3 Al 2 4 - dark red;
Grossular Ca 3 Al 2 3 - light green, greenish brown, yellow
Spessartine Mn 3 Al 2 3 - pink;
Almandine Fe 3 Al 2 3 - the most common of the garnets, the color is pale red-lilac, raspberry;

2) Zirconia:
Kimzeite Ca3Zr2 12.46 4.0

3) Vanadium:

goldmanite Ca 3 V 2 3
yamatoite Mn 3 V 2 3

4) Chrome

knorringite Mg 3 Cr 2 3
uvarovite Ca 3 Cr 2 3 - emerald green;

5) Glandular
mejorite Mg 3 (Fe,Si) 2 3
andradite Ca3Fe23 - dark red-brown, to black titanium - andradite varieties (melanitis and sherlomite- jet black..

Crystallographic characteristic

Syngony. Cubic. 3L 4 4L 3 6L 2 9PC

Symmetry class. Hexahedral O h -m3m

Crystal structure

The structure of the garnet was first studied by Menzer using the grossular as an example. AT recent times the structure was refined in the study of grossular and pyrope.
The lattice is body-centered. The structure is based on isolated silicon-oxygen tetrahedra and oxygen octahedra with trivalent metals. Divalent metals are located in the cavities of a framework of tetrahedra and octahedra and are surrounded by eight O atoms. Each oxygen atom in the structure is bonded to a Si atom, one trivalent and two divalent atoms. On the block selected for simplicity of the image, which is 1/64 of the unit cell of the grossular, the Al atoms occupy the vertices, the Si and Ca atoms occupy the middles of the edges. Ca atoms, each of which is surrounded by eight oxygens, form polyhedra in the form of Thomson "twisted" cubes. Oxygen atoms occupy the tops of octahedrons (with Al inside in the grossular); octahedrons are connected by triangular prisms, on the side square faces of which Ca atoms are located; infinite columns of prisms and octahedra are extended along non-intersecting triple axes. These columns are parallel to cube diagonals with mutual angles of 70°30" and are connected by "twisted" cubes (with Ca inside) and isolated silicon-oxygen tetrahedra.
When refining the garnet structure, it turned out that its polyhedra are distorted: silicon-oxygen tetrahedra are tetragonal bisphenoids elongated along fourfold axes; The Al octahedron is a trigonal antiprism extended along the 3rd order axis; Ca(Mg)-ky6 is distorted so that the angles between its faces in pyrope range from 76 to 119°. According to Abrahams and Geler, the distortion of Ca-polyhedra in uvarovite is less than in grossular, while in andradite the polyhedra are even less distorted, or only tetrahedra are distorted. In pyrope, the distortion of polyhedra is as strong as in grossular. The energy of the crystal lattice was considered on the example of pyrope and grossular.
Natural or synthetic products with a garnet structure are known for 40 elements. The position of individual cations in the structure is considered by Geler. Among artificial compounds with a garnet structure, substances are known whose octahedral positions include: Ca, V, In, Sc, Al, Fe, Cr, Mg, Mn 2+ , Mn 3+ , Rh, Co 2+ , Ni 2+ , Cu 2+ , Zr, Ti; Ca in garnets can be replaced by Mg, Fe, Cd, Ba, Sr, Th, Zr, Ge, Mn 2+ , TR from Gd to Lu; TR from Tb to Lu are part of the garnet in combination with Al (Lu 3 Al 5 O 12 ), from Nd to Lu and Y - in combination with Ga (Lu 3 Ga 5 O 12 ) or with Fe 3+ replacing Si ; Si is replaced by Ge, Ga, Fe, Ti, Zr. Among the minerals isostructural with garnets: berzelite - (Ca, Na) 3 (Mg, Mn) 2 (AsO 4) 3, griffite - (Mn, Na, Ca) 3 (Al, Mn) 2 3 and cryolithionite - Na 3 Al 2 (LiF 4 ) 3 .

Main forms: the most characteristic and most common form is d (110), as an independent form, n (211) is often found. The forms a(100), o(111), e(210), r(332), and s(321) are less common.

The form of the pomegranate in nature

Crystal Shape

Facets of garnet crystals in order of decreasing abundance, according to Shafranovsky: (110), (211), (321), according to Donay-Harker: (211), (110), (321), (100). Distorted crystals are often observed. Uneven development leads to the formation of flattened - mainly along (111), dipyramidal and lenticular crystals, elongated along the fourfold axis.
The d(110) faces are often striated parallel to the long diagonal. On the (211) faces, hatching parallel to the (211) : (110) edge was observed, and on some faces there were growth steps or etching patterns. The nature of the growth stages differs in garnets of various origins. In sedimentary rocks, garnets with a stepped (tiled) surface are found.
On crystals of uvarovite, andradite, and grossular, d(110) is more often observed; pyrope, almandine, and spessartine are characterized by n(211). The appearance of crystals may depend on the geological conditions of mineral formation. The development of individual faces on garnet crystals presumably depends on changes in the relative concentrations of R2+ and R8+ in solutions: with an increase in the concentration of R3+, the (211) faces predominantly develop on the crystals, and with a relative excess of R2+, the (110) faces develop. On garnet crystals from the Lyangar deposit
(Uzbekistan) observed a change in shape (110) in the core to (211) in the outer cut. Inverse relationships are noted for garnet from the river. Akhtaranda in Siberia.

Doubles. The crystal structure of garnets excludes the existence of twins. The twins according to (111) described by Kobel and Artsruni and Hedl are probably intergrowths.

Mineral inclusions

Garnets often contain inclusions of other minerals: vesuvian, calcite, quartz, magnetite, epidote, diopside, chlorite, biotite, feldspars, pyroxenes, muscovite, amphibole, titanite, disthene, staurolite, apatite, zircon, rutile, etc. Sometimes garnet is only a crust or perimorphosis surrounding the core, which is composed of other minerals; such sheath-like crystals have been found in skarns.
Some inclusions of minerals in metamorphic rocks have the form of smooth S-curved bands (the so-called “snowball” structures), which indicate the simultaneity of crystallization under mobile conditions. Pomegranate lorphyroblasts contain inclusions that differ in the time of formation. The presence of gas-liquid inclusions was noted.
Its natural intergrowths with various minerals were observed: (211) garnet parallel to (001) muscovite], (110) and (001) garnet parallel to (001) and muscovite; garnet parallel to rutile elongation; (211) garnet parallel to (0001) corundum; (211) and garnet parallel (010) and topaz. Intergrowths of pyrope with diamond are known. Regular intergrowths of garnet and orthoclase were observed: the (110) face of garnet is almost parallel to (001) of orthoclase; intergrowths of garnet with quartz (in pegmatite veins of the Dzirul massif and the Southern Urals). Skeletal intergrowths of garnet with bytovnite (written structure) are described.

Aggregates.

Physical properties of pomegranate

Optical

Color often red, brown, yellow, green, black; colorless rare. The color of brown tones of calcium garnets of the grossular-andradite series can be caused by ferric ions in six-fold coordination; for calcium-free garnets - almandines, pyropes and spessartines - predominantly red tones are characteristic; coloration can be caused by iron and manganese ions, as well as chromium and titanium.
The color of almandine is caused by Fe and Mn ions in octahedral coordination or by Fe ions in "twisted" cubes. The color of the pyropes is explained by the isomorphic admixture of Fe and Mn, which can be included in "twisted" polyhedra or octahedrons; Cr and Ti can also influence the color. The coloration of spessartines is probably caused by Mn 2+ and Mn 3+ in six-fold coordination, Fe 2+ in eight-fold coordination, and Fe 3+ in six-fold coordination. The green color of uvarovite and demantoid is caused by chromium. With a small content of chromium, which replaces aluminum, the color is red; at more content Cr changes the size of the octahedron, the color becomes green. In uvarovite, in contrast to pyrope, Al and Mg substitute for Cr and Ca, which leads to a red shift of broad absorption bands.

trait missing. The color of the powder is white or light shades.

Shine glass, sometimes close to diamond or diamond.

Low tide oily, resinous,

Transparency. transparent in varying degrees to opaque.

Mechanical

Hardness 6-7.5. Fragile

Density 3.18-4.28, depends on composition. In andradites, the density proportionally increases with increasing content of Fe 2 O 3 .

Cleavage is usually absent; sometimes there is imperfect cleavage or separation according to (110).

The fracture is semi-conchoidal, uneven or splintery. They break into pieces with sharp edges.

Fragile, crumbly in granular aggregates, in dense (cryptocrystalline) masses are very strong.

Chemical properties

With brown and phosphorus salts, many of them react to Fe and Mn; with phosphorus salts, they form a silica skeleton. They react weakly with HCl, with the exception of demantoid. When exposed to HCl (for several hours), different acid resistance of the minerals of the group of this group a was noted; it increases in the direction of andradite - pyrope - grossular. After calcination, HCl readily decomposes with the release of gelatinous silica. They decompose when fused with Na 2 CO 3 or K 2 CO 3 .

Other properties

The magnetic susceptibility of iron-magnesian garnets is proportional to the iron content. Artificially obtained minerals with iron in the octahedral and tetrahedral positions are ferromagnetic. Y 3 Fe 2 3 has especially strong ferromagnetic properties; in this compound, all iron is trivalent; the magnetic moment is 2/3 of the magnetic moment of magnetite, the Curie point is 545° K. Y 3 Fe 2 3 single crystals have a fine domain structure. The elasticity coefficient increases with increasing temperature.
In infrared absorption spectra, individual bands shift to the region low frequencies with increasing cation radius. All of them are characterized by three main absorption bands: the position of the band 1142-1003 cm -1 does not depend on the composition; the position of the bands 1006-775 and 927-786 cm -1 depends on the composition (for garnets of the pyralspite series 1006-951 and 927-868 cm -1 , for garnets of the grossular-andradite series 927-882 and 868-786 cm -1 ). In the region of 350-280 cm -1, garnets of the pyralspit series give weak absorption bands, which are absent in garnets of the grandite series. In addition, there are three absorption bands at 4500, 6000 and 7800 cm -1 due to the presence of Fe 2+ in eightfold coordination.
In the ultraviolet region of the spectrum, they give a number of narrow maxima; all of them are characterized by a maximum of about 22,700-22,800 cm -1 . In the andradite-shorlomite series, the absorption is directly dependent on the content of titanium in the quadruple coordination.

Average temperature of decripitation from various deposits: grossular - 393°, uvarovite - 440°, andradite - 487°, almandine - 607°, pyrope - 615°, spessartine - 646°.

Diagnostic signs

Easily recognizable by isometric crystals, high hardness, lack of cleavage.

Satellites. Diopside, hedenbergite, epidote, vesuvian, wollastonite, actinolite, chlorite, hedenbergite.

Origin and location

They are among the most important rock-forming minerals. They are formed in a wide range of temperatures and pressures and in various media. Participate in the formation of many mineral deposits. Pyrope is a typomorphic companion mineral of diamond in kimberlites.
They are observed in some igneous rocks as their primary component(in basic rocks - pyrope, in granites - spessartine and almandine, in alkaline rocks - melanite and shorlomite). Spessartine is most common in pegmatites; some of them showed garnetization of plagioclases. Garnets of later generations are characterized by an increase in the andradite component. The dependence of the composition of garnets from pegmatites on the physicochemical conditions of their formation is noted.

Most widespread have a contact-metasomatic formation, mainly formed as a result of the interaction of acidic magmas with carbonate rocks. Grossular and andradite are especially characteristic of such formations. They occur as continuous masses or are included in skarns along with diopside, hedenbergite, epidote, vesuvian, wollastonite, actinolite, chlorite, etc. Different skarns differ in composition. Thus, andradite (in association with salite) occurs in skarn lead-zinc and copper-iron ore deposits, and substantially grossular garnet (in association with hedenbergite) occurs in skarn scheelite and molybdenite-scheelite deposits.
When acidic magmas acted on basic metamorphic rocks, almandine was formed along with biotite, hornblende, feldspars, sometimes with pyroxenes, tourmaline, sulfides, etc.
Quite often they are contained in schist; the composition depends on the composition of the original rocks; if the original rocks are rich in Al and Fe, almandine is formed, with the metamorphism of calcareous rocks - grossular; high content of Mg and Al is favorable for the appearance of pyrope.
Pyrope-almandine-spessartine garnets (pyralspites) are characteristic of three metamorphic facies adjacent in terms of thermodynamic conditions: amphibolite, granulite, and eclogitic. Spessartine is typical for the amphibolite facies, almandine predominates in the granulite facies (it can contain up to 45% of the pyrope component and up to 23% of the grossular component), and the eclogitic facies has a pyrope-almandine component (the garnet associated with kyanite contains a significant amount of the grossular component). Accordingly, it is recognized that with an increase in the degree of metamorphism, the content of the pyrope component increases and the content of the spessartite component decreases. When studying the MgSiO 3 - CaSiO 3 - Al 2 O 3 system, the enrichment of the pyrope component coexisting with clinopyroxene and orthopyroxene was confirmed with an increase in pressure to 70 kbar at a constant temperature, as well as with a decrease in temperature at a constant pressure. The content of pyrope ranges from 81 mol. % at 18 kbar up to 88 mol. % at 71 kbar and 1400°.
Under conditions of polymetamorphism (during diaphthoresis), the composition changes depending on the degree of rock alteration and temperature. During low-temperature diaphthoresis, the composition does not change; it is replaced only by a fine-flake aggregate of sericite a and chlorite. The manganese content of garnet, in addition to thermodynamic conditions, depends on the content of manganese in the original rock. Miashiro's statement about the decrease in the content of the spessartine molecule with increasing pressure is unreliable.
With an increase in the degree of metamorphism, the molecular volume and a0 of garnets decrease, Ca 2+ and Mn 2+ are replaced by smaller Fe 2+ and Mg 2+ and, apparently, the ratio (CaO + MnO) : (FeO + MgO) is an indicator of the degree of metamorphism . According to other authors, such an indicator is the Mg/(Mg+Fe) ratio. In garnet-biotite and garnet-hornblende associations, the distribution of Fe and Mg depends on the degree of metamorphism. In staurolite-garnet shales, the distribution of Mg in staurolite and garnet can serve as a temperature indicator. In coexisting biotite and garnet, with increasing temperature, Al 2 O 3 passes from biotite to garnet, and Fe 2 O 3 - from garnet to biotite. In metamorphic rocks, as a result of progressive recrystallization, very large crystals are sometimes formed.

Mineral change

Secondary minerals formed after garnets include: epidote, micas, hornblende, scapolite, orthoclase, calcite, quartz, chlorites, serpentine, dolomite, magnetite, hematite, cordierite, sillimanite. During weathering, they are destroyed difficultly, with the formation of clay minerals. Grenades make up a substantial part heavy fractions of a number of sedimentary rocks.

Practical use

The described group of minerals of high hardness (almandine, pyrope, spessartine, and to a lesser extent andradite) are used as an abrasive material. Rocks containing more than 10% of well-formed large crystals (more than 1 cm) are considered suitable for the abrasive industry. They are floated with Na oleate (pH 11.5 and above), distilled tall oil soap oxidized with petrolatum (pH 3.5); 90% of the mined mineral is used to make paper or cloth for polishing hard wood, polishing mirror glass, polishing leather, hard rubber, celluloid and other products.
Transparent and beautifully colored minerals of the group (hessonite, pyrope, grossular, uvarovite, almandine, demantoid) have long been used in jewelry. In connection with their use as ferrimagnets, numerous works have appeared on their synthesis, especially rare-earth ones.

Physical research methods

ancient methods. Under a blowpipe, all the minerals of the group, with the exception of uvarovite, melt with greater or lesser ease and form glasses painted in various colors. Andradite and almandine are fused into a magnetic ball.

Crystal optical properties in thin preparations (sections)

In thin sections, andradite, grossular, and spessartine are colorless or pinkish, brownish, rarely pink, or red; melanite - brown or red-brown, uvarovite - green. They are isotropic or anomalously anisotropic. The refractive indices vary from 1.73 to 2.01 and depend on their composition. According to Zyuzin, there is the following dependence of the refractive indices on the composition: n = 1.815-0.00099 (pyrope) + 0.00015 (almandine) -0.00085 (grossular).
In optically anomalous stones, birefringent stripes are observed, parallel (110) or forming an angle of 60 or 90° with the trace of the (110) face, as well as regularly fading sectors, the bases of which are the (110) faces.
Optical anomalies are explained by the difference in the chemical composition of individual zones of single-crystal individuals and the resulting stresses in the crystal lattice. The orientation of the optical indicatrix depends on the direction of the voltage, and the magnitude of the birefringence depends on the magnitude of the voltage. If the birefringent stripes are perpendicular to the trace of the d(110) face or form an angle with it, then optical anomalies appear to have arisen only as a result of stresses in the crystal itself. Stresses arise when the garnet is cooled after its formation.
According to Korzhinsky, grenades containing<40 % андрадита (показатель преломления <1,807), изотропны или слабо анизотропии; гранаты, содержащие >60% andradite (n>1.837), isotropic; grenades with 40-60%. andradite molecules are highly anisotropic and exhibit a sectorial structure. These conclusions are confirmed by the study of artificially produced garnets.
When heated to 750-850°, the anisotropic garnets from Tyrna-Auz became isotropic. Abnormal interference coloration of stones is usually gray; n g - n p \u003d 0.002-0.012. Artificial rare earth garnets have birefringence from 0 to 0.002 and 2V-5-20°. In the wavelength range 486-656 microns, the dispersion of refractive indices for members of the pyrope - almandine - spessartine series ranges from 0.016 to 0.023, for members of the grossular - andradite series from 0.032 to 0.034; the dispersion of the refractive indices does not depend on the iron content.
Ingerson observed iridescence in garnets - the result of light interference in thin plates parallel to (110) and (111). Some minerals show asterism caused by the diffraction effect due to inclusions of very small, not exactly defined elongated crystals, the elongation of which is parallel to the axes of symmetry of the garnet. Asterism most often manifests itself in the form of a four-ray, six-ray or eight-ray star, in some almandines - in the form of 12 four-ray stars, each with angles between the rays of 70 ° 32 "and 109 ° 28" '. In garnets in reflected light and dark field, "twisted asterism" was also observed (the result of inclusions of small "twisted" deformed crystals).
The angle of rotation of the plane of polarization in infrared light is about 10°.›