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Growing ruby crystals and other artificial stones at home. Growing crystals is a great opportunity to get rich

In terms of their physical properties and chemical composition, synthetic gemstones practically do not differ from natural ones. Not all products sold in jewelry stores contain natural stones. And this is quite normal. Consider how to open your own ruby crystal growing business at home.

The main problem is that most natural stones do not have all the necessary characteristics to show off in jewelry. Stones obtained in the factory or laboratory have almost the same characteristics. In addition, the synthetic production of jewelry is cheaper than the extraction of natural in deep and life-threatening mines.

Growing with limited salts

Potassium alum is suitable for this method. At home, it is best to grow crystals from copper sulfate. They do not grow well from ordinary salt. But copper sulfate is easy to buy, and very beautiful blue artificial gems grow from it.

1. We prepare the container. We will make a saturated salt solution in it. Pour a few tablespoons of salt, pour it with water and stir. Add salt until it no longer dissolves. Use hot water so as not to make a mistake with the proportions. There are solubility curves for different salts. They show how many grams can be dissolved in 100 ml of water at a certain temperature.

Solubility Curves

2. Filter the solution. This step is very important, especially if you are buying blue vitriol from a gardening store. If the solution is dirty, the crystal will grow with defects. We leave the solution for a day so that excess crystals fall out of it. They settle at the bottom of the glass and serve as a seed for us (the main elements on which new ones will grow).

3. We tie the crystal to the fishing line. We wrap the fishing line on a pencil and hang this device on a glass with a saturated solution. Over time, the water evaporates, the saturation of the solution increases. An excess of a substance that cannot dissolve settles on our product.

4. Once every two weeks, add a saturated solution to the glass. Why do it? Over time, the water evaporates and at some point in the growth it will not be enough and the growth will stop.

Important! The solution added should be the same temperature as the solution where the crystal grows. If it is the highest, we can ruin everything.

5. After three months, we take out the crystal and dry it with a towel.

6. We cover the product with 1-2 layers of colorless nail polish. This is necessary so that it does not dry out and does not lose its luster. After drying, the product can be taken by hand.

Here are some wonderful rubies you can grow at home!

Ruby is one of the most famous and beautiful gemstones that has been highly valued by people for many thousands of years. Its bright red color is associated with the color of fire or blood and symbolizes vitality and energy. Natural rubies are rarely large and transparent, so especially outstanding stones become national treasures in different countries, adorn the things of royal families and aristocrats.

Description of natural and synthetic rubies

Natural ruby is a very hard mineral, a type of corundum. Its chemical composition is very simple - it is aluminum oxide Al 2 O 3 with a microscopic admixture of chromium, which provides a red color.

Colorless corundum has no jewelry value, but due to its hardness, it is used in technology as an abrasive material. Other jewelry varieties of corundum are sapphire, the blue color of which is provided by an admixture of titanium and iron, and a pale green artificial amarillo.

Rubies range in color from pink to fiery red and brown, and the most expensive shade is considered to be “pigeon blood”: bright red with an admixture of purple. Products made from this stone have a characteristic glassy luster.

In addition to the beautiful color, the ruby is characterized by an interesting optical phenomenon - the manifestation of a six-pointed star on a smooth curved stone surface (asterism). This is due to superpositions of light refraction within the crystal. Star rubies are not cut but left as cabochons.

Natural stones are rarely of perfect quality, therefore, before they go on sale, they undergo various types of processing. The most popular techniques are heating, enriching with beryllium to enhance the red color, and filling cracks in low-quality stones with glass.

Currently, most of the "natural" rubies on the market are composite, as they have gone through a process of filling with glass, the mass of which can eventually reach up to 50 percent of the mass of the stone. Natural ruby is the most expensive gemstone after diamond. The record-breaking 25-carat stone was purchased in 1995 by the Sheikh of Brunei for $12 million.

Synthetic rubies are stones that are identical to the natural mineral in their chemical composition, but obtained artificially. The first small crystals of ruby were obtained by Mark Gooden from a corundum melt back in 1837. Later, scientists learned how to fuse fragments of natural stones into the so-called "Siamese rubies".

Using this method, the French received jewelry stones weighing up to 10 carats. However, the first truly artificial alumina ruby was obtained only at the end of the 19th century by Auguste Vernel. His method allowed the rapid growth of large crystals on an industrial scale and initiated the widespread production of synthetic rubies around the world.

The main modern methods of growing rubies

Currently, a number of industrial methods are used for the synthesis of gemstone crystals, for example:

Synthetic rubies are used in industry for the production of solid-state ruby lasers.

Due to quantum transitions in a ruby crystal during irradiation, such a laser generates a directed beam of red light with a wavelength of 694.3 nm. Since 1960, this device has been used in the medical industry (tattoo removal) and for solving various technical problems (pulse holography).

Fake rubies: how to distinguish a synthetic stone from a natural one?

The surest way to tell if your stone is synthetic or natural is to consult a professional jeweler. Since the chemical composition of an artificial ruby is identical to a natural mineral, it is not always possible to reliably verify the origin of a stone at home.

There are some useful tips on how to determine the authenticity of a ruby yourself. First of all, you need to carefully examine the stone in a strong magnifying glass or under a microscope. A tenfold magnification with good lighting will suffice. Synthetic rubies are usually flawless, while natural rubies have minor surface imperfections or cracks. Bubbles and inclusions inside the stone also indicate its artificial origin.

Due to the high price and popularity, other minerals are often sold under the guise of rubies, which are much cheaper. Among them, the most common are:

garnets (Karelian rubies). Dark red or crimson stones that have a rather dull color. They are softer than rubies;
tourmaline. The mineral is red-pink in color, also inferior to ruby in hardness;
red glass;
composite rubies. These are low-quality natural rubies, the cracks in which are filled with colored glass.

There are several rules on how to distinguish a ruby from a fake, especially if it is not made very well. First of all, pay attention to the cut: a genuine stone should have precise and honed edges, while its imitations can be rounded and smoothed. Another test method is the determination of hardness.

Ruby is a very hard stone and leaves colorless scratches on a glass or ceramic surface, while a coin does not leave a mark on it. If your stone leaves a red streak on the glass, this indicates that it is artificially dyed. Ruby differs from glass in density (it is one and a half times heavier) and hardness (it easily scratches glass).

Unfortunately, without special equipment, it may not be possible to distinguish a high-quality fake from a natural ruby. Until the 19th century, such methods did not exist at all, therefore, in many historical relics, crowns and jewelry, other red gems are inserted instead of rubies.

The magical and healing properties of rubies

Rubies are traditionally endowed with magical properties among different peoples. Buddhists believed that this stone awakens a person's ability to art. Indian magicians believed that with the help of this stone one can gain power over other people. Often rubies are considered a symbol of passion, love and energy, sometimes the noble intentions of its owner are associated with it. This gem gives strength and protects against black magic.

Medieval physicians used rubies to treat epilepsy, paralysis, and even depression. Large stones were infused in water, and this infusion was used to treat bowels and impotence. Modern traditional medicine believes that wearing rubies normalizes the functioning of the circulatory system and has a beneficial effect on the heart.

However, for the stone to work, it must be natural, since artificial rubies are devoid of magical and healing properties.

Due to the high value of natural rubies since ancient times, various imitations and fakes have been massively entering the market. At the end of the 19th century, the cultivation of rubies, chemically identical to natural ones, was invented.

To date, there are many ways to grow large and transparent crystals, which are used both in the jewelry and technical fields, for example, in the production of ruby lasers. However, a natural ruby costs much more than an artificial ruby and remains preferable for the manufacture of elite jewelry or magical talismans.

Growing ruby crystals at home is available to everyone. The work does not require an equipped laboratory, the acquisition of theoretical and practical knowledge in the field of mineralogy, the purchase of special chemicals. Everything you need can be found in the kitchen.

Home experimentation

It is advised to start growing rubies with small volumes. First, experience is gained, the whole process is understood, and then direct systematic work begins. Synthetic creation of your own hands will not be inferior in beauty and attractiveness to natural minerals. Stones are in demand among jewelers, so a successful experience can bring additional income if you find a market.

There are several ways to grow. It is advised to try all the options, then stop at the one you like.

Artificial precious rocks created by man do not differ from natural ones in terms of chemical content and physical properties. The advantage of home technologies is that they allow you to create perfectly pure breeds. In nature, this happens very rarely. The jewelry qualities of laboratory specimens are quite good. Another plus of the mineral is the cost. The stones are cheaper than their originals, which originate in deep mines.

organic salts

It is easy to grow a ruby crystal from various salts:

copper sulphate;
potassium alum;
regular salt.

The longest salt-based process, the most beautiful samples are obtained from vitriol. The production of ruby crystals is based on the following steps:

Tank preparation. It should hold salt and a saturated water-salt solution. Take hot water. The process is gradual. Dilute two tablespoons with water, mix thoroughly. Then salt is added and mixed. it is necessary to shower until the salt ceases to dissolve. To keep the proportions, they take a hint: a table of the solubility of different salts in 100 ml of water, their relationship with the temperature of the liquid.
Solution filtration. The solution must be clean. Dirt impurities will spoil the structure of the stone. It will show defects. The solution remains for 24 hours. During this period, crystals form at the bottom of the container. They will become the basis of the ruby.
The growth of an artificial mineral. A fishing line is tied to the stone formed at the bottom of the glass. It is wound on a pencil or wooden stick. The device is installed on the tank. The crystal is in solution, suspended. Water tends to evaporate, a saturated saline solution releases excess, which is fixed on the resulting sample.
Adding a salt solution. Water always needs a certain amount, if it becomes scarce, the crystal will stop growing. At normal room temperature, water is added once every 2 weeks.

To get rubies at home, you will have to wait about 3 months. Then the stone is freed from saline solution, dried with a soft cloth. The sample is covered with a colorless nail polish in several layers.

Council of experienced crystal makers. The salt solution must be at the same temperature as the water in the container. The crystal grows at a slightly lower temperature, but high rises in solutions spoil and stop growth.

Apparatus for work at home

To create rubies at home, you will need an apparatus named after its creator, Verneuil. The inventor's technique allows growing a ruby weighing 30 carats in 3 hours. Technology has made it possible to create precious material in the right amount. Industrial facilities began to actively implement the development of Verneuil. Time has made its own adjustments, and today such a device is easily assembled at home. Components of the device:

cathetometer;
shaking mechanism;
bunker;
burner;
muffle;
growing crystal;
crystal holder;
crystal lowering mechanism.

The device is used to grow not only rubies. Often blue topaz, emeralds and stones with a translucent transparent structure are created in the device.

Home production process:

The powder is poured into the hopper through the funnel. Powder composition - Al2O3, additional component - Cr2O3.
With the help of a burner, a flame is supplied to the bottom of the bunker.
The powder starts to melt.
The layers of molten powder are a growing ruby crystal.

Through the lowering mechanism, the artificial mineral moves down. In the device you can get different shades. The rate of crystal formation is higher than in the tank. It will take only 3 hours, and you can admire the ruby. For one sample, the following volumes of components are needed:

6 g Al2O3;
0.2 g Cr2O.

Raw crystalline formations are extraordinary in shape. They are originally similar to natural, but at the same time always unique.

Working with the device at first glance is complex and painstaking. In fact, a device invented by a French inventor more than 100 years ago will not create any special problems. It is assembled from parts that practical people have on the farm. Making an apparatus and purchasing powder are the main stages of preparation.

Economic calculations

Home technology is always cheaper. You can calculate the cost of all components, costs, and determine the approximate cost of the samples received. What is taken into account ruby:

the cost of parts of the device;
electricity costs;
price for the purchase of powders for the base of the crystal.

Even approximate calculations will show the benefit. The cost of all components will not be 500 rubles. For such money it is difficult to buy a ruby jewelry of a beautiful appearance and excellent quality. The process should not frighten home experimenters with legality. Natural minerals are regulated by the state, synthetic minerals are not subject to documents. If a decision is made to open a small production, it should be registered in the prescribed manner. The soul will be in place, the work will bring only satisfaction.

A gemstone created by yourself will become a pride. The craftsman will gradually learn to change the shades of rubies. The next step will be creative work on the received samples, the transformation of their interior design items and original decorations.

Auguste Verneuil method
Determining the competition in this area
Register home production
promotional activities
A detailed method for growing crystals at home!

Growing with limited salts

Solubility Curves

4. Once every two weeks, add a saturated solution to the glass. Why do it? Over time, the water evaporates and at some point in the growth it will not be enough and the growth will stop.

Important! The solution added should be the same temperature as the solution where the crystal grows. If it is the highest, we can ruin everything.

5. After three months, we take out the crystal and dry it with a towel.

6. We cover the product with 1-2 layers of colorless nail polish. This is necessary so that it does not dry out and does not lose its luster. After drying, the product can be taken by hand.

Here are some wonderful rubies you can grow at home!

Auguste Verneuil method

To obtain a ruby in the laboratory, an apparatus invented by the French scientist Auguste Verneuil more than 100 years ago is used. On the Internet you can find information on the method of growing ruby and more simplified equipment of a French scientist, which can be used at home. According to the method of Auguste Verneuil, in 2-3 hours you can grow a ruby crystal, the mass of which is 20-30 carats. It should be noted that this method also applies to the production of topaz of various shades (yellow, blue, white and transparent).

Drawing of the Verneuil apparatus

To get a product weighing 30 carats, you need 3 kWh of electricity and 3 hours of time. In monetary terms, this will be less than $ 1. For the production of one crystal, 0.2 g of chromium oxide and 6 g of aluminum oxide powder are needed, the cost of which will be no more than $ 0.50.

You don't need to be an economist to understand that if even an uncut crystal is sold to a jeweler, the profit will be very solid. Having pleased your wife with home-grown topazes and rubies, you will receive incomparable psychological "dividends".

Download a detailed description of the Verneuil method

Technology for the production of synthetic sapphires, rubies and corundum

Single crystals of lamellar sapphire (colorless corundum) are grown by melt methods, which makes it possible to obtain crystals weighing up to several kilograms. Synthetic sapphire single crystals are grown from aluminum oxide by stretching with molds of a given profile according to the Stepanov method. As a colorless structural material, lamellar sapphire is used in semiconductors and the electronics industry, thin-film hybrid and integrated microelectronics, lighting engineering, chemical equipment manufacturing, and other industries.

Plates of optically transparent and colorless corundum (sapphire) vary greatly in price depending on the presence of micro-defects invisible to the eye. The average size of the plates is 170x170 mm and the height is 30 mm. The complete formation of high-quality raw materials is carried out in about a week. A plate with microscopic defects invisible to the eye (visually absolutely perfect) is quite suitable for use in jewelry as a raw material, but may not be suitable for the needs of fine industrial optics, so the price of raw materials will vary greatly. What is ideal for jewelry and realistically priced may not be enough for industrial needs.

At the beginning of growth, sapphire crystals are colorless, but then, as impurities accumulate, they become slightly pinkish. And if you put pinkish corundum for some time under an ultraviolet (UV) lamp, then the pinkness gradually turns into a wonderful wine brownishness. The color of sapphire is like wine topaz, only harder.

Sapphire single-crystal plates, according to the growing technology, resemble the process of freezing ordinary water and its modifications. If it is the "sparkling water" type, there will be a lot of bubbles visible to the eye. If it is of the "tap or open source" type, there will be many hidden and invisible bubbles that make the sapphire unusable under a microscope. The type "water with foreign impurities" will give impurities in the sapphire. The ideal option - the type "distilled water without gas and impurities, in a vacuum" - is used to make magnifying and reducing glasses for burning chips and processors of modern computers (Intel in the USA, reports at seminars and symposiums in 2006-2007 and later ). Very relevant.

Single crystals of synthetic corundum are a modification of aluminum oxide, in which a small part of the aluminum ions can be isomorphically replaced by ions of the iron group or copper ions. Growing synthetic single crystals of a wide range of colors (rubies, sapphires, topazes, amethysts, etc.) is carried out by the Verneuil method. Synthetic corundums are used in the jewelry, watch and instrument making industries. Corundum waste is used to produce high quality abrasive and refractory products. The Verneuil apparatus also makes it possible to grow synthetic spinels and the like.

Ruby and sapphire are minerals that, although they differ in appearance, have an identical crystal structure and properties, except for the presence of minor concentrations of impurity elements that give them their characteristic colors. Ruby and sapphire consist mainly of aluminum oxide Al2O3, the crystalline form of which mineralogists call corundum. Crystals grown by the Verneuil method known as Buli, apparently due to the fact that initially they had a rounded shape. This term, coined by Gaudin and used by Verneuil, has become common among crystal growers, despite the fact that crystals are now cylindrical.

Verneuil grew Bouli weighing 2.5-3 g (12-15 carats) within 2 hours. The boules were round in shape, and some of them had a diameter of 5-6 mm. Today, cylindrical boules with a diameter of 20 mm and a cylinder length of 50-70 mm and the so-called semi-boules (half of a cylinder cut lengthwise with a base of 10 x 20 mm) are grown. The volume of such a semi-boule 10 x 20 x 60-70 mm is 10-11 cubic meters. cm and weight, respectively, 40-45 grams. This raw material is not yet measured in carats (but it can be easily recalculated - the mass is 200-250 carats).

Monocrystalline transparent boules and rods of artificial corundum (synthetic rubies and sapphires) are obtained by melting and recrystallizing alumina (aluminum oxide) in an oxygen-hydrogen flame. Boules can be additionally colored: with impurities of Cr (chromium, up to 2%) ions - in red, V (vanadium) - in grayish green in daylight and purple in artificial light, Mn (manganese) - in yellowish pink, Ni ( nickel) - in yellow, Ti (titanium) - in pink-violet colors. When cutting synthetic corundum under different names (sapphire, ruby, topaz, alexandrite, amethyst), they are used in jewelry; red corundums - rubies - as reference stones for mechanical watches and other precision instruments, and rods - in optical generators (lasers). The density of synthetic corundums is 4 g/cc, the hardness is 9 for colored corundums and 9.25 for moissonite (the hardness of diamond is 10 on the Mohs scale). The crystal structure of corundum is composed of Al (aluminum) atoms surrounded by 6 O (oxygen) atoms, which form the densest hexagonal packing. Corundum is also characterized by high chemical resistance and high melting point (2020-2050 degrees C, refers to refractories).

Institute of Crystallography of the Academy of Sciences of the USSR. A. V. Shubnikov developed methods for the synthesis of corundum, with the help of which corundum crystals of various shapes are obtained. This method makes it possible to grow leucosapphire crystals in the form of large plates with a certain predetermined crystallographic orientation. The molybdenum container filled with the starting material is placed in a vacuum furnace where it is heated to over 2000° C. The alumina is melted. The container with the melt slowly moves to areas with a lower temperature, and when the temperature drops to a certain value, the melt crystallizes. For directional crystallization, a seed crystal is introduced into the melt. The whole process is automated.

On an industrial scale, artificial corundum materials are obtained by melting bauxite in electric furnaces with a reducing agent (iron filings). They are also used as abrasives; using powder metallurgy methods, they are used to make cutters for machining metals at high temperatures. They are not suitable for the jewelry industry (for cutting as inserts).

It turns out that not only natural natural stones are being faked now. Since, after the collapse of the USSR, the prices for synthetic corundum raw materials became quite high, the prices for synthetic corundum, sapphires and rubies also turn out to be not cheap. The photo on the right is a typical example. counterfeits of synthetic single crystals of corundum(synthetic rubies and sapphires). Pretty bright colors and characteristic goltovka (shape resembling rounded pebbles). It seems to be similar to corundum, and it can be sold expensively, but it was not grown using the Vernel method.

If someone still has Soviet-cut synthetic rubies (stones made in the USSR) in jewelry, do not rush to get rid of them. You have an example of an excellent machine-cut stone and a rare example of valuable synthetic corundum. Now you can’t just buy them in a jewelry store. Today, the prices for cut synthetic corundums, rubies and sapphires for jewelry are many times higher than the prices for traditional colorless and colored cubic zirconias (synthetic cubic zircons), although they are noticeably cheaper than the prices for natural raw materials and natural gemstones of the corundum group.

Technological features of corundum production

Auguste Verneuil method. The year of birth of industrial synthetic ruby is 1905. Verneuil's technology consisted in the use of a vertical burner with the supply of alumina powder into the flame through an oxygen stream. The powder is shaken in the gas flow under the action of an electrically driven vibrator. The use of a gas-tight rubber gland allows the shock of the vibrator to be transmitted to the vessel containing the alumina powder without oxygen leakage. A ceramic pin is placed in the cold part of the flame, on which drops of liquid alumina are collected, which are formed during the melting of the powder that wakes up through the hot zone of the flame.

The flame is surrounded by a ceramic shield, which plays the role of an insulator and protects the growing Bulya from drafts. This muffle is equipped with a viewing window, which was sealed with mica in the original Verneuil apparatus. Excessive heating of the upper part of the apparatus due to the heat flow from the hot zone is prevented by the use of water cooling.

In the initial stage of Bouli's growth, the powder, falling on the pin, hardens and forms a cone from a material of relatively low density. Subsequently, the cone is moved to the hot zone of the flame, where its top begins to melt. At this point, several crystals are formed, but one of them is oriented in the direction of the highest growth rate. It inhibits the growth of other crystals and serves as a seed for the developing Bulli. The skill of the operator is extremely important in the early stage of growth, as the flame temperature or powder feed rate may need to be adjusted during crystal selection.

After the predominant growth of one crystal begins in the central part, in order to increase the diameter of the Bouley, increase the feed powder feed rate and gradually increase the flame temperature by adjusting the oxygen flow rate. The upper surface of the Boule becomes rounded, and fresh portions of alumina are fed onto it in the form of falling melt drops. Next, the stand with the stem is lowered at a speed corresponding to the growth rate of the Bouley. The most important condition for growing high quality crystals is the uniform supply of the powder, so much effort is spent on preparing the feed material so that it has good flowability.

If the powder is too coarse, the incorporation of large cold particles can cause a thin molten layer to solidify. Then many small crystals are nucleated and Bulya loses the structure of a single crystal. The use of too fine powder is associated with the danger of evaporation of alumina in the flame. The optimal particle sizes lie in the submicron range (less than thousandths of a millimeter - 20 microns). The particles must have the correct shape, since only in this case they react equally to the impact of the vibrator (and pour evenly). Verneuil obtained alumina from ammonium alum containing about 2.5% chromium alum impurities (classic red boules were obtained). A powder of this composition was heated until the decomposition of alum and the formation of oxides, which were crushed and sieved through a wire sieve to select particles of the required size.

Czochralski method(melt pulling method) is as follows: the melt of the substance from which the stones are supposed to crystallize is placed in a refractory crucible made of refractory metal - platinum, rhodium, iridium, molybdenum or tungsten - and heated in a high-frequency inductor above the melting point. A seed from the material of the future crystal is lowered into the melt on the exhaust shaft, and synthetic material is grown on it to the desired thickness. The shaft with the seed is gradually lifted up at a speed of 1-50 mm/h with simultaneous rotation at a frequency of 30-150 rpm -1 . Rotate the shaft to equalize the temperature of the melt and ensure even distribution of impurities. Crystal diameter up to 50 mm, length up to 1 m. Artificial garnet, as well as corundum, spinel, chrysoberyl, lithium niobate, etc. are grown using the Czochralski method.

A large number of scientific papers have appeared on the cultivation of corundum and spinel flame melting method(zone melting method). In the process of growing crystals by this method, a small area - a zone - is melted using a heating mechanism, and then the heater moves along the sample, in connection with which a single crystal grows sequentially. There are two variants of this method: in the method of horizontal directional crystallization, a long narrow boat is used (the resulting crystals are in the form of plates measuring 220x100x20 mm or more, depending on the size of the boat), in the vertical version - a floating zone - a sintered rod (boule) is used, fixed in the upper and lower parts.

The main attention is paid to the relationship between defects in crystals and the conditions under which Boole is grown. The main imperfection of this method of growing crystals is the presence of a stepwise temperature gradient between the hot region of the flame, where the molten top of the Bouley is located, and the colder lower part. A sharp change in temperature along the Bouley axis creates strong stresses in the crystal and, when removed from the furnace, the Bouleys often crack (along the cylinder) with the formation of two semi-cylindrical fragments (half-boules). For the needs of the jewelry industry, such semi-boules are quite suitable for cutting.

Technological features of the production of star sapphires (asterixes)

In 1947, the Linde branch of the Union Carbide Corporation in East Chicago began producing star sapphires and rubies using the Verneuil method. In 1949 this method was patented. Starstones are named for their unusual appearance when viewed along a crystal along its major axis. Six brilliant stripes radiate from the center of the crystal so that an impressive picture is created, corresponding to the symbolic image of a star or asterisk. Very bright star stones are obtained, which are absent in nature.

Such a phenomenon in corundum is caused by the presence of thin needles of rutile - aluminum titanate (Al2TiO5), which are elongated into strips located in accordance with the symmetry of the crystal structure at an angle of 60 o relative to each other. This is achieved by adding small amounts of rutile to the alumina powder. During the formation of the boule, rutile dissolves in the molten layer of alumina, but upon cooling after crystallization of the boule, it precipitates in the form of needles, but mainly in the form of Al2TiO5, which is formed as a result of the interaction of rutile and alumina. According to the Linde patent, the best results are achieved by adding 0.1% to 0.3% rutile to the powder and then annealing the boule at 1100-1500°C for several hours to isolate Al2TiO5 needles. Starstones are usually made in the form of fairly domed cabochons, in which case they are most spectacular.

The main difficulty in the manufacture of star stones is to achieve a uniform distribution of Al2TiO5 needles so that the star occupies the entire width of the stone. Linde experts have found that the best results are achieved by varying the oxygen flow rate, which results in periodic temperature variations. The most convenient way to do this is with a valve that partially shuts off the oxygen supply. This procedure was found to result in a periodic change in the distribution of needles. If, at a low flow rate of oxygen, the needles are distributed over the entire width of the boule, then a high flow rate favors their crystallization only in the peripheral part.

The most spectacular star pattern appears when the thickness of alternating layers is 1 mm. This procedure demonstrates one of the main advantages of artificial gemstones over natural gemstones: the crystal grower controls the conditions for making the material and can change them to achieve the best result. Lovers of natural crystals admit the possibility of certain treatments of stones to improve their appearance, such as heating zircon, but they do not have the ability to control the conditions under which the crystals originally grew. Only in rare cases can a natural star stone compete with its man-made counterpart in purely visual perception.

Linde makes starstones in another way, when a pre-cut cabochon from a stone synthesized without additives of rutile is immersed in a rutile melt in order to form a very thin layer of needles. Only after that is the final polishing done. Such stones differ from ordinary star stones in greater transparency, but are not sold on a large scale.

In addition to ruby and sapphire, Linde's star stones are available in varieties of purple, green, pink, yellow and brown, as well as smoky blue and smoky red. Since the original patent has now expired, a number of other suppliers have emerged, for example in Germany. A colorless star sapphire has been reported. Such competition caused the price of synthetic star corundums to fall. The Linde firm has ceased their production and sold their equipment, although stones from the Alvin Company of New Jersey are still available for sale. Apparently, at present, the main supplier of star stones, which are still very popular in the USA, is the Jeva company.

Synthetic gemstones are virtually indistinguishable from natural stones in their chemical composition and physical properties. The whole problem. It turns out that among natural precious stones, not all of them have sufficient purity and other gem qualities to be honored to be presented in jewelry stores, and in laboratory or factory production, the technological process can be debugged so that all crystals grown in the laboratory will have almost the same jewelry characteristics.

And in production they are much cheaper than their "colleagues" of the same quality, mined in deep and life-threatening working mines. In addition, deposits of certain minerals are not scattered in abundance evenly over the entire globe, but are concentrated, as a rule, in a few places.

Growing ruby crystals at home

Further thought flowed by analogy with stained-glass windows and mosaics. If on the Internet I came across offers for these services from large reputable companies with solid production facilities and cash flow, then I asked myself why it was impossible to make small stained-glass windows (inserts in interior doors, wall lamps, etc.) literally on your desk?

I studied the technology, puzzled over how it can be simplified for home use, conducted a certain number of experiments - and got the result!

Similarly, Alexander and I began to creatively rework the idea of growing gemstone crystals at home. We studied (at an introductory level) different methods, and settled on the method of the French scientist Auguste Verneuil, who created more than 100 years ago an original technique and equipment that made it possible to grow ruby crystals weighing 20-30 carats in 2-3 hours. This was an outstanding achievement of science and technology, not only because it made it possible to artificially produce such a valuable material in the required quantities, but also because it opened up prospects for the synthesis and growth of crystals of other precious stones.

The success of O. Verneuil was preceded by almost half a century of research on the synthesis of ruby.

The simplicity and reliability of the Verneuil method led to the rapid organization of the industrial production of these crystals, first in France, and later in almost all highly developed countries of the world.

The first figure shows the very principle of the Verneuil method (isn't it - everything looks quite simple!), And the second picture shows the Verneuil apparatus.

The principle of operation of the Verneuil method

Verneuil apparatus

It looks quite complicated, even at first it inspires some fear - they say, I would never do such a thing! But these are false fears. After all, it should be remembered once again that the inventor created his technology more than 100 years ago!

Naturally, he did not have at his disposal those electrical and mechanical "tricks" that are available to any home master at the present time!

It was on this problem - how to simplify the Verneuil apparatus through the use of modern electrical components and mechanisms of wide availability and create a "kitchen" version of the apparatus - that we began to work.

And we succeeded!

The site http://rubin-bmm.narod.ru contains more detailed information on our "kitchen" version of the Verneuil apparatus.

Using the Verneuil method, you can grow crystals not only of ruby, but also of blue, white (transparent) and yellow topaz (as well as other shades as desired).

I am publishing a detailed description of the "kitchen" version (with the consent of Alexander) as the main generator of the idea and I am not at all afraid of competition from those enthusiasts who decide to follow this idea. The reason is very simple: at present, artificial precious crystals are grown in many countries of the world, but as soon as you go to a jewelry store, it will immediately become obvious that prices are still "biting". And the saturation of the market, apparently, is still very, very far away. And even if after reading this information there are several thousand enthusiasts, then with our "home" production, we all cannot make any special "weather" in this market segment. Therefore, the results of our research can be published without fear of anything. On the contrary, if something like the "Association of Home Crystal Growers" appears on the net :-), then it will be even more interesting and useful for everyone, since, as you know, two heads are good, and two thousand - one can confidently assume - much better. And some of these heads may turn out to be much lighter, and their ideas will help everyone who is interested to further simplify and improve the device, and turn it from a "kitchen", for example, into a "bedside table" :-).

Now a few words about the economic efficiency of the project. To grow a ruby crystal weighing 20-30 carats (4-6 grams!), it will take 3 hours and about 3 kWh of electricity. Calculate how much it costs in your area. Think. that the figure will be less than 10 rubles. The cost of 6 grams of aluminum oxide powder and 0.2 grams of chromium oxide generally cannot cost more than 50 kopecks.

So if you, dear reader, offer even an uncut crystal to an interested jeweler, then you don't need to have a Soros head to understand that the profit from the transaction will be very solid. Well, if one of the handmade men makes his wife or girlfriend happy with rubies and topazes, then the psychological dividends from such "investments" cannot be counted at all! :-).

A few more words about the legal legality of such proceedings. Of course, I still have to thoroughly consult with lawyers, but in the law of the Russian Federation “On PRECIOUS METALS AND PRECIOUS STONES” that I reviewed (last amended on July 18, 2005 N 90-FZ) it is stated very specifically that the object of regulation of this law are diamonds, emeralds, rubies, sapphires and alexandrites, as well as natural pearls in raw (natural) and processed form. Unique amber formations are equated to precious stones in the manner established by the Government of the Russian Federation. This list of gemstones can only be changed by federal law.”. Specially singled out the word - "natural". Nothing is said about synthetics.

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