Artificial sapphires: what is it and how do you get it?

Synthetic sapphires are widespread in the jewelry market. Natural stone is considered precious and has a high price. The alternative option also looks noble in products, and according to aesthetic characteristics, it is not much inferior to the first option.

Natural gem is formed in a specific environment for millions of years. The price for it is sky-high, and demand is still good.

Water, heat and powerful pressure form ore veins. They serve as clusters of different crystals.. In the deposits of sapphires there are also liquid gases that circulate in an enclosed space for many years.

In laboratories creating nanomineral scientists reconstituted natural conditions. But for a grown crystal to be a decent size, it takes several months. Nano sapphires grow faster, and therefore cheaper than natural counterparts. The cost of artificial stones is lower, but not so much as to compare them with ordinary glass. The purity and depth of the color of artificial crystals is better than that of genuine minerals. Hydrothermal sapphire does not require additional refinement, like a stone with genuine properties. These methods, by the way, are expensive and require additional investments.

Artificial sapphire is a kind of corundum. It is also the basis for rubies and emeralds. Sapphires have a blue color due to titanium and iron. Heated beryl is also involved in the synthesis. Taking into account the conditions of production, we can say that synthetic stone is not grown, but boiled. At the base of one of the mixtures is aluminum oxide, which looks like an ordinary white substance. It will turn into sapphire only at a temperature of 2200 degrees Celsius. The crystallization rate of artificial sapphires is 4 mm per hour. For large crystals you need a lot of time. In the future, if necessary, they are cut into pieces and treated, giving the similarity with natural deposits.

The basic method of producing artificial crystals requires a special furnace Verneuil. It has been used for decades. In this method, alumina is melted in a flame of a hydrogen-oxygen burner. In the furnace Verneuil make liquid drops. With gradual cooling, they form a crystal. In addition to sapphire, this technology is also suitable for the production of ruby, as well as other precious stones. The difference is the addition of impurities of various metal oxides, which give a suitable color.

The widespread dissemination of technology began around 1932, and especially intensified during the Second World War. By production the mix of initial materials with the set physical and chemical qualities is used. Homogeneous components that are loaded into the unit are called “charge”.

The size of microparticles in the composition of the mixture from 1 to 20 microns. A portion of the powder is poured into the bunker, which has holes. Through them, substances enter the furnace, where hydrogen is burned. The mixture is melted and grows the seed crystal.Capacity for seed rotates, providing uniform growth and warming up. As it grows, the seed is at the bottom, and the upper part is transformed into faces.

The form in which the charge is located resembles an expanding cone. Depending on the consumption of the base material, long crystals are obtained in it. In addition to the flow, important are parameters such as the flow of gases and the speed of rotation, the quality of heating. The method has the characteristic advantages:

• the ability to control the growth of crystals visually;
• burning temperature is automatically controlled;
• Fluxes and expensive crucibles in the finished material are absent.

Disadvantages of the method:

• due to high temperature internal stresses appear in the crystal;
• due to violation of system rules in the preparation of the charge, volatile substances may evaporate, and the subsequent recovery process is impossible.

The resulting shape and size of the crystals usually corresponds little to the parameters of manufactured parts. Therefore, the processing of materials is almost always necessary. Conventional lathe, milling or drilling machines are not used for machining. Products are brittle, therefore only abrasives are possible. Diamond disks or grinders, suspensions or special pastes can be used.

Typically, particles of an abrasive material are pressed into the surface of the material being processed. It forms microcracks, which are moved inwards during the process. Further actions result in a whole network of cracks. They close, causing chipped individual sections. They are removed in layers from the surface, giving the product the desired shape.

Abrasive materials intended for processing, knowingly divided by hardness.

Experts choose the desired abrasive on the mineralogical Mohs scale. According to the principal differences of minerals, diamond corresponds to the tenth grade, and corundum - the ninth grade. For the treatment of sapphires suitable special grinders or suspensions.

Grinders are cast iron, glass, steel, copper or brass parts with abrasive micro-powders. The grain size of the micropowders can range from M14 to M5. After grinding a grown crystal, you need to polish it. For this process, an abrasive slurry is selected, which is rubbed into the surface until it is completely evenly distributed. Polishing is carried out in two stages, for which different abrasives with coarse or fine grain size are chosen.

Artificial corundum, as well as natural deposits, is blue or dark blue. Laboratory analog is a popular imitation, which is difficult to distinguish. Specialists grow a synthetic product without chipping and damage, and jewelers like this quality. You can check the product by external indicators:

• the artificial mineral has a more perfect and pure shade;
• there are practically no internal defects in it;
• if there are liquid formations, then they are correctly spherical in shape, whereas in natural deposition there are practically no such formations;
• If one considers very carefully genuine and synthetic sapphires, they can be distinguished precisely by their quality, and natural stones necessarily contain various natural inclusions that are not found in laboratory stones.

At the same time, the chemical and physical properties of both species are completely similar. Experts distinguish nuances that are hidden in the wrong structure of growth. The hardness of the authentic and laboratory stone is different.

Genuine minerals give out 1,762 - 1,778.

Another method involves the use of a special liquid. Monobromonaphthalene is placed in a container that is set against the background of white paper. Visible curved colored stripes speak of the artificial origin of the stone. Shortwave ultraviolet can also be used. Under its action, this stone will not change color. The grown sample will turn white or dirty green. Glow may be a red tint. It depends on the impurities used in the composition of the mixture.

In connection with the development of the technology of growing artificial sapphires, it becomes difficult to distinguish them with the available techniques. Only professionals who have the appropriate skills can draw full conclusions. Knowledge of certain properties of a stone can also help.

Artificial sapphire has intrinsic properties identical to natural stone. In addition to the jewelry industry, it is widely used in watchmaking or as a semiconductor material. All semiconductors are characterized by high sensitivity of electrophysical qualities. Semiconductors are actively used in circuits for various techniques. Almost all modern integrated circuits contain semiconductor elements.

Crystalline substances have the ability to conduct electric current, but with temperature changes, the action of light rays, the presence of impurities of other substances. Scopes of semiconductors are extensive: radio engineering, optical electronics. In alternative medicine, sapphire is known as an antidote against many toxic substances. The healing qualities of sapphire since ancient times have been used to acquire pure thoughts, spiritual peace and balance, to gain selflessness.

Cornflower blue sapphire is considered one of the most difficult stones for laboratory reproduction. Creating this shade is impossible without thorough training. Technical data must be observed in exact measure. The natural stone of a similar shade is available only in India. In this country he is a ritual and ceremonial amulet. It is chosen for the treatment of heart failure, gaining psychological stability. If you keep the stone in the house, well-being will definitely come, and the homeowner will have the lead. The most beautiful natural samples of sapphires are stored in special funds of such countries as:

• Thailand - 16 kg;
• Sri Lanka - 18 kg;
• USA - 15 kg.

In Russia, there is a cornflower-blue sapphire, produced in the XIX century, it is stored in the diamond fund of the country. The stone is characterized by incredible strength and durability. At home, jewelry with sapphire require additional care. For jewelry, regular moisture, direct sunlight, and dust are harmful. Products can be improved by regular cleaning. For soaking, ordinary soap solutions or shower gels are suitable. Means used must then be rinsed with cold water.

In jewelry stores, you can find special tools for the care of precious stones. They are usually in the form of sprays or disposable wipes. Means are expensive, so their use is liquid with heavy contamination of jewelry. Since sapphire rarely loses its original gloss, it is enough to use ordinary household cleaners that every hostess will have.

Watch the video to learn how to grow artificial sapphires.