jewelry factory

jewelry factory
An "summary" material produced in a laboratory that has usually the same physical and chemical properties of the corresponding natural, for example, "synthetic beryl variety emerald.As a result of this extreme similarity between the different physical properties, analysis, and thus the identification is based mainly on the observation of internal features, or through the use of additional tests that would normally fall outside the normal routine search.For "artificial product" we mean a product without the corresponding natural laboratory, a material that does not exist in nature, with the sole function with good credibility to imitate the appearance of a substance (usually) very popular in the market.The history of synthetic products, and related methods of synthesis, is concentrated in the last hundred years, but it is right to point out how the technology of synthesis has recently reached milestones so advanced as to obtain products so good, and so "similar" to the corresponding natural to mislead not only jewelry but sometimes even "gemologists" not sufficiently prepared.E 'undeniable fact that they still qualified gemological laboratories ability to identify these products as the latest generation, in each example there are elements of recognition that, if read carefully, it can uniquely reveal the genesis of natural or synthetic.To arrive at a correct diagnosis must still emphasize the need for a culture gem that can adequately support the search for differences, not necessarily detectable only by the physical data, which sometimes differ only insignificantly, but also the use of sophisticated equipment where access is possible, in most cases, only a small number of professionals.Much easier the recognition of artificial products because most of the physical and optical data are markedly dissimilar from the buds whose external characteristics (color, brightness, etc..) Want to emulate.Here is a description of the materials for information most frequently used, with the essential information for the analysis of the first level.
SUMMARY OF THE DIAMOND
For at least three hundred years are made in the laboratory experiments to produce diamonds, transforming the carbon in that diamond, which burns at a temperature of 800 degrees centigrade, it turns into carbon dioxide.Lavoiser known French physicist, in 1776 showed that the diamond and graphite have the same chemical formula but different crystalline structure. The next step was to try to transform graphite into diamond.In 1953 some technicians in the company of the Swedish company ASEA managed through the use of special equipment that provides high pressure and high temperatures. The crystals so obtained are small, however, from 0.01 to 1.2 mm and could only be used as abrasives for industrial applications.Later other companies like De Beers in South Africa, Diamant Boart in Belgium and especially in America, General Electric modified this method to obtain better results.In the '70s, General Electric began to develop a new technique called "BELT - type apparatus" by which he could produce synthetic diamonds weighing over a carat. However, the cost far exceeded that of natural diamonds, and the production of crystals for gem use was not followed.E ', however, important to stress that the final push to the production of synthetic diamonds was not a commercial, but strategic for the war industry and in any event for all those technologies that require high precision and extreme performance, the tools (and abrasive) to diamonds are absolutely essential. Space technology, an example for all, would not exist without the work that make extensive use of this indispensable mineral. The situation changed in the '80s, when the need to produce chips for computers in this material, completed research towards the development of synthetic diamond crystals ever larger: the leader in this sector has become the first Japanese company Sumitomo for them available in commercial quantities.E 'must however be noted that the degree of color was not very interesting, however, not to involve the gemstone market, and that those with good saturation in yellow were the easiest to produce.In the late 80s the American company General Electric could still produce a chemically pure diamond (type II A) and basically colorless.It goes back not so long ago the announcement made by Thomas Chatham, owner of the firm specializing in the production of synthetic gems, would start with Russian partners, in Siberia, the production of synthetic diamonds of gem quality, and its statement of intent to to market with a mass of synthetic diamonds over one carat in lower prices by 10% compared to the natural counterparts, caused some shock among the diamond traders.Since then, however, does not know anything and probably the only real thing is the development of a new production technique (known as "termogradiente Bars"), where high pressures are necessary for the crystallization of diamond produced by the injection of fluid in a compression chamber and not through a press giant.The great advantage of this method is to be significantly less expensive earlier, thus shortening the gap between the economic natural and synthetic diamond.Until now, synthetic diamonds are then used only for industrial purposes, but we can not exclude the use, in a not too distant future, even in the jewelry sector.E 'latest news to arrive in the West of the latest products of Russian industry: synthetic diamond crystals of good quality, with very advanced features, with good size. For now, the specimens that cut shall not exceed seventy cents, but were already in an advanced stage of crystal growth which will be nearly four-carat rough.A dozen specimens were examined in Antwerp, and as many in America, while two samples were passed recently in our laboratories, in Valencia. These two diamonds were cut very well and beautifully finished, marked by yellow-gold to brown-green, and looked very pleasing to the eye.For the ultraviolet rays presented a curious figure with glowing green, very unusual geometric shapes: a four corners to which branched four smaller squares.Even under the microscope was a visible loss of particular white powder, with thickening according to the geometry of the faces of a pyramid, whose base was clearly visible under the microscope through the table of these diamonds.Density and thermal conductivity are identical to those of natural diamond, and magnetism entirely absent.Two examples are certainly insufficient to draw general conclusions, and the more analytical process to assume dedicated "ad hoc", but the purpose of these details is to emphasize that synthetic diamonds are now a reality with which we must soon confront, and from that time to take the necessary precautions.But, and here we return to law in matters that concern us more closely, synthetic diamonds, in general, can be identified and distinguished from natural?Feasible in laboratory gemological analysis using highly specific recognition of these modern synthesis, however, remains very difficult, if not impossible for the average jeweler.These, although fairly qualified and equipped with technical equipment certainly sufficient to identify the synthesis of colored stones and diamonds in the quality of graduation, almost certainly could not achieve, in this case, sufficient diagnostic confidence.The identification is now possible to search through the optical characteristics of the particular: the growing areas to cross or hourglass, a typical greenish fluorescence, (also a cross, the stronger the wave not long ones), special inclusions in mostly metal (not found in natural ones), as well, when present, a significant magnetism.Above all, a characteristic infrared spectrum, is among the most frequent diagnostic findings that distinguish the natural from the equivalent plastic.The recognition of these substances remains a problem of the analysis by professionals, who are also responsible (and especially!) The constant and timely update of methods - scientific and technical - on the thorny issue.At the conclusion of the argument is hardly necessary to add that De Beers, to protect itself adequately to what, at least in perspective, may (could) be a problem, has already made a couple of devices suitable for safe identification of synthetic diamonds.Still at the prototype stage, and for now assigned to laboratories of trust with the task of thoroughly tested, from most recent news we can already say that they are able to give reliable results, with a remarkable ease of use, which, as soon as commercially available, will make them attractive not only for gemological laboratories, but also for jewelers more attentive to the evolution of specific technologies.
SUMMARY OF RUBY
Currently on the market are synthetic rubies produced by different methods: we list below the most common way of information highlighting the most typical characteristics for the purposes of proper identification.Not without underline the continuing evolution of the production process requires constant updates and special caution before signing the final diagnosis. The initial search, which then gave rise to these synthetic industry, was motivated by a specific request for the watch, which served highly resistant materials to be mounted under the moving parts of clocks.
Flame fusion method (Verneuil) method and the draft (Czochralski):
Although completely different methods of production, the material obtained has the same characteristics, so as to be shown in practice, not just commercially, without any distinction.Among other things, the production process for both methods has a low cost that also explains the wide use of these synthetics.These jewels are on the market since the early 900 and is not uncommon for vintage jewelry. With physical and optical properties very similar to the natural, a relatively easy detection is possible only through an analysis under the microscope. Characteristics of these gems, especially those of more recent (past two years) are: a total absence of inclusions, if present, these consist of streaks of growth curves, gas bubbles of different shapes (very small and willing to "cloud") and tension fractures.
Floating zone method:
The crystals produced by this system have appeared within the last twenty years, mainly by the Japanese company Seiko to finalize the initial production (colorless crystals) to the "glass" protective watch.At this time the birth of the term "mineral glass" for the scratch-resistant material used on the dials of watches, time is still wrong because of the nature of the material, both for its origin.A fundamental characteristic of the crystals obtained with this method is the complete lack of internal characteristics. An interesting application of this method involves an operation of "refining" of the bars of material obtained by the Czochralski method, so that they were "cleansed" of those internal characteristics typical (and unintended) that characterize them.
Method in flux:
Appeared on the market in the early '60s, the crystals obtained with this method are as credible as to make identification sometimes very challenging even for the gemologist.Their resemblance to the natural high that is so often were passed off as such, and successfully, from unscrupulous operators.The physical-optics are the same as natural and, not infrequently, even the inclusions can be similar enough to not lend itself to easy identification, even by analysts experienced and better equipped.When present and clearly identifiable, the most significant interior features are:
- LAMINETTE platinum metallic finish in geometric shapes,- Straight and parallel lines of growth similar to those of natural- Dark inclusions in the form of "veil" is often convoluted,- Two-phase inclusions incorporated in the veil of dark,- Negative crystal geometry,- Inclusions "dust"- Crystalline inclusions of nutrient.
The main manufacturers of synthetic of this type are: Chatham, Kashan and Ramaura (USA), Douros (Greece) and Knischka (Austria).The cost of the gems obtained with this method is quite high: for information purposes only, and for a medium to high quality, we can say that is usually above 60 € per carat.
SUMMARY OF SAPPHIRE
As for ruby, synthetic sapphire is the most common one obtained by the Verneuil method.This synthesis has characteristics such as bubbles rounded, flask-shaped, torpedo streaks and curves that, unlike the Verneuil ruby, are more or less broad, blurred and irregular. This summary is typical bluish fluorescence, white or greenish-looking "chalky," says the short-wave ultraviolet.The other type of synthesis, similar to that used for the ruby, is based on crystallization in flux, but to date has not yet had an adequate business momentum: this is mainly due to high production costs, the difficulty in 'obtain large material (which unlike the ruby, in nature, it is possible to find) and, finally, by the formidable presence in the market with sapphires "termodiffusi" whose production cost, in many cases is less than that of synthetics.The inclusions are the same as that found in ruby ​​obtained in the same way as, for example, consist of droplets of dark feathers look more or less elongated, flat LAMINETTE crucible, usually platinum contour generally hexagonal, triangular, irregular ( like small sticks).The producers are the most important companies and Chatham Kashan, both American.
SUMMARY OF CORUNDUM
To complete the argument of corundum, remember the market presence of crystals where the color goes throughout the whole spectrum: the specimens produced using either the Verneuil, Czochralski is the most modern, so the chemical and physical characteristics are similar to the corresponding natural.Beyond one (in some cases) suspected fluorescence, attention should be paid to the gemologist and research to identify the internal characteristics.For the avoidance of dangerous illusions, features internal diagnostics, already rare in natural samples, are even less frequent in these synthetic products.Going for exclusion is obvious that, at least in large specimens, a total absence of internal characteristics, even at high magnifications, must arouse the least suspicion of the analyst, thus encouraged to further, more detailed investigations.Since the '50s, synthetic corundum products are marketed by the methods mentioned above which have an attractive, nice star effect, usually more pronounced than in the corresponding natural.Even in this case, the microscopic analysis is perfectly adequate to dispel any doubt.
SUMMARY OF BERYLLIUM VAR. EMERALD
Synthetic emeralds on the market are currently produced by two entirely different methods, but the results were highly valuable for both, so as to show a high degree of "credibility" for traders with good experience!
Method of crystallization in flux:
Companies Gilson, Chatham and Zerfass are among the most important for the production of crystals obtained by this method and contendendoselo with products from Japan and the former Soviet Union, share the world market.The samples crystallized in dark chocolate, whose size may exceed the inch, have a dress very similar to that of crystalline natural, but they tend to have values ​​of density, refractive index and birefringence generally lower, albeit slightly.In this brief presentation chelsea filter is usually a deeper red color, and ultraviolet light a more pronounced red fluorescence.But it is a microscope that can see the most significant diagnostic differences compared to the natural.Inclusions typical of the crystals obtained with this method and still the most common are:
- Phenacite crystals with prismatic or rounded appearance,- Small plates of metallic finish, usually platinum,- Residues of flux, with typical aspect of "icing" or "flag", with any two-phase,- Straight and parallel lines of growth,- Structures and growth plans,- Color zoning,- Wedge-shaped two-phase, with crystal phenacite end wider.

Hydrothermal method:
Among the manufacturers of emeralds synthesized by the hydrothermal method are the most important Lechleitner, Linde, an unidentified Russian manufacturer, and lastly, the Australian company Byron.This is the best known and which one is currently the largest commercial deployment.The physical and optical properties of gems obtained by this method are quite comparable to those typical of natural gemstones, especially those coming from the most famous Colombian mines.For this reason even the most precise and careful analysis of the indices of refraction and the density is of no comfort in the identification of products obtained by hydrothermal synthesis.Therefore, it is only through a thorough examination under a microscope that can reach a unique identification, which is almost always at the cost of a very challenging research.Interior features that meet frequently are:
- Crystalline inclusions of phenacite, also look to nail- Presence of a seed crystal, or its traces,- Liquid inclusions, with two-phase,- Straight and parallel lines of growth,- Structures for growth, with typical "for tire tracks" or "spearhead"- Color zoning,- Traces of precious metals.
Less frequent but equally important and ongoing study, additional tracks are the result of continuous development of this method.
Fairly easy to recognize, and cited as the most historical non-technical, are a couple of products in vogue until a few decades ago: the emeralds produced by the company and Lechleitner known as Type 1 and Type 2.Consisted of a crystal of beryl already faceted nature, usually of low quality and lacking in color but with good clarity, covered with plastic as a function of dye, the second type, known as "wafer" was built by crystallizing synthetic material around layers of natural beryl almost colorless.These specimens, when received, are easily recognizable, especially immersion microscopic examinations, but remember that their appearance when they were already sold on embedded objects including the honor had considerable success and created quite a few disappointments to customers (at least ) unwary.There are still a significant moment in the history of synthesis, and each has at least one gemologist, almost by way of affection, as well as for study.Unlike some synthetic corundum, on the market at prices much lower, emeralds, whatever the method of synthesis, have prices far greater: in any case exceed EUR 60 per carat, for smaller sizes.Unfortunately, it is these that, statistically, have the best chance to subtly filter between the routine checks of the trade to get there, maybe mixed with natural ones, until the unsuspecting end user.Certainly it is precisely the specimens from the smaller ones that create the greatest difficulties in identifying the analyst, it is imperative to have high-class equipment and the time needed to achieve not only reliable but also irrefutable.
As a curiosity, also cite the Morgan and the aquamarine synthetic Byron produced by the company that, although already known and analyzed by some gemological laboratories, because of their high cost of production does not appear to be commercially available.Still represent a significant example of productive capacity, and are subject to collection for study purposes.
SUMMARY OF chrysoberyl VAR. ALEXANDRIA
For many years, using an imitation of Alexandria, following which, however, appears to be a normal shot synthetic corundum (among other things, low price), then with the physical and optical properties are quite different.The actual synthesis of alexandrite is very rare and very little in common trade, especially since the alexandrite is sought almost exclusively in a small market of collectors.Among the most important synthesis we still want to mention that using the fusion method with fondant, whose physical characteristics and optical crystals almost comparable to those of nature.Except, of course, for inclusions in synthetic feathers are made of fondant, LAMINETTE platinum hexagonal or triangular in outline, straight and parallel lines of growth, dark inclusions without defined shapes, as well as other, less common, however, .Worthy of mention is the alexandrite produced in Japan (Inamori - Kyocera) and known as "vert. Crescent alexandrite, which is obtained by the method Czochralsky (draft).This product does not pose a significant diagnostic features, but an almost complete absence of inclusions.As a curiosity, still remember the existence of a variety of synthetic alexandrite, obtained by the hydrothermal method.In the '80s, finally appeared on the market the variety of synthetic chrysoberyl gatteggiante, produced in the laboratories of the Sumitomo Company, the effect of chatoyancy was achieved with the addition of an additive whose nature is still unknown.
SUMMARY OF SPINELLO
In the history of synthesis, the spinel obtained by the Verneuil or Czochralski occupy an important place not only for the variety of colors obtained, but also (and perhaps especially) for the spread that had the product as a result of industrial standardization of production processes.It 'still curious history of trade of synthetic spinels, whose ubiquity was (and perhaps still is) arising from the use as an imitation of other gems, and not as a synthesis of the natural crystal itself.In support of this assertion, it suffices to note how the "synthetic aquamarine", the "pink synthetic France", some in imitation of the emerald green doublets, up to a dark blue material (sintered in imitation of lapis) are actually spinels synthetic.Chemically, to be truthful, we should speak of "spinelloidi" because the chemical formula is slightly different from the typical variety of specimens of natural gemstone.As a result, the density and refractive index are slightly different. Characteristic of this method are a refractive index of 1.727, a density of 3.63, a strong, anomalous birefringence typical inclusions and classical methods described above: curved striae, gas bubbles of different shapes, clouds, etc..Much less frequent, quite a rarity in education, are the synthetic spinels themselves and appeared on the market during the '80s.These products, produced by the method of casting flux, physical and optical characteristics of similar magnitude to those of all natural "gem quality" and therefore such as to mislead in the case of hasty superficial analysis or, worse, only superficial. Almost always red, these specimens are identified as the main element of the inclusions characteristic of this method, which are:
- LAMINETTE platinum metallic finish, in geometric shapes- Two-phase inclusions incorporated in the veils of dark- Dark inclusions in the form of "veil", often twisted- Negative inclusions of nutrient.
However this? Latest product on the market is low, and because production costs make it uncompetitive with the natural equivalent, is (or above) for the reduced demand for spinels from the operators.
SUMMARY OF QUARTZ
Assuming that in nature, quartz is the most common mineral crystallized, and therefore very cheap, its interesting piezoelectric properties make it a material of extreme importance for the electronics industry.The question that ensued prompted the industry to develop techniques for the synthesis of quartz improved so as to ensure the availability of crystal characteristics (purity, mainly) extremely improved, in the quantities needed and in time fully programmable.The quality of material produced by the hydrothermal method, has also pushed the industry that revolves around the jewelry to the consideration of industrial production as raw material which may also be used in ornamental.Normally colorless crystals from industrial, the step to the marketing of colored crystals was brief, and are now available in various colors.Historically, the first synthetic quartz specimens were to appear on the market green and blue, immediately recognizable as such because it does not exist in nature as crystals with intense color saturation, in addition, the spectroscopy, the quartz synthetic blue show the typical spectrum of cobalt.Later appeared on the market of synthetic quartz yellow (citrine), dark brown (fum? Is or smoked) and purple in various shades (amethyst).The recognition of these crystals, optical and physical characteristics are perfectly comparable to those of the corresponding natural, it is sometimes difficult even by expert analysts.The certainty is reached only when present in the sample can be found details of the typical natural (inclusions "a tiger's coat," twinning plans with characteristic orientations), or residues of the production process as inclusions "a crumb of bread or particular liquid-looking feathers.Unfortunately, the above inclusions are not always present because the material is synthetic and the natural one of the highest quality, often appear perfectly crystallized, and therefore devoid of even the minimum necessary internal conditions for a unique identification.In any event, the use of an infrared spectrophotometer is of considerable help to dispel doubts residues in difficult cases, and this machine (expensive, and highly-specialized) is then used only when you have to consider lots of value particularly high.
SUMMARY OF DIFFERENT MATERIALS
At the conclusion of the argument should make a brief overview on the materials produced by industry, whose use in jewelry is not uncommon and the perfection of which has often caused many problems in iterating commercial operators are not sufficiently updated.To be fair descriptive divide the argument that a specific criterion: the synthetic replicas of natural materials and artificial products that have no equivalent in nature.The opal is certainly the synthetic product, which first struck the attention of analysts and traders, from the late '60s, they had to compare their knowledge with more and more refined products of the company Gilson, theoretically varieties produced in black and white "fire", but only type marketed "Harlequin" for the best similarity with the corresponding natural.The synthetic opal (Gilson, but also the Japanese Inamori) physical characteristics (hardness and density) slightly different from the natural, but the recognition will work primarily with careful observation under the microscope, looking for the effect "in lizard skin ", the" texture "distinctly columnar, the zoning of the particular color ripple, and so on.Another is the success of Pierre Gilson Lapis lazuli, whose massive appearance on the market is somewhat later than the Opals.The product, which has a very good color, it is more porous and softer than the natural, for which also shows a lower density (2.38 against 2.70 to 2.80 of nature).Although quite damaging to the sample, the test is easier for the recognition of the synthetic product, is to see the lively effervescence with a particular smell of rotten eggs (for the development of hydrogen sulphide) occurred in contact with a drop of hydrochloric acid