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Янтарь и Копал, сходство и различия
Администратор Eve: Копал — твёрдая, трудноплавкая, имеющая химическую стойкость, похожая на янтарь ископаемая природная смола, выделяемая преимущественно тропическими деревьями семейства бобовых. Часто копал называют по месту добычи. Добывают копал подсочкой стволов дикорастущего копалового дерева, также из земли (ископаемый копал). Слово происходит от copalli (благовоние) языка мексиканских индейцев. Копал без вкуса и запаха, светло-желтого до бурого цвета, состоит в основном из смоляных кислот, плотность 1,03—1,07 г/см3, плавится при 180—340°, растворимость различна. Служит для приготовления лаков; в связи с появлением синтетических смол утрачивает своё значение. До сих пор копал используется в Мексике и Центральной Америке как благовоние в различных церемониях. Существует несколько вариантов копала. Твёрдый, похожий на янтарь, жёлтый копал — наиболее дешёвый вид, белый копал — твёрдая, липкая субстанция молочного цвета — более дорогой. http://ru.wikipedia.org/wiki/%D0%9A%D0%BE%D0%BF%D0%B0%D0%BB_%28%D1%81%D0%BC%D0%BE%D0%BB%D0%B0%29 Мадагаскарский копал Балтийский янтарь — самый распространённый и массовый вид янтаря в мире (около 80 % всех видов янтаря), обнаруживаемый в балтийском регионе. Его собирают преимущественно вдоль южного побережья Балтийского моря (Калининградская область России, Латвия, Литва, Польша, Германия и Дания) Возраст балтийского янтаря оценивается в 44 млн.лет (Эоцен).[2] Было подсчитано, что те древние леса произвели более 105 тонн янтаря.[3] Из янтаря в XVII веке с помщью перегонки была впервые получена янтарная кислота. Соли и эфиры янтарной кислоты называются сукцинатами (лат. succinum — янтарь). Поскольку балтийский янтарь на 3—8% состоит из янтарной кислоты (Succinic acid), то его также называют сукцинит. C 1850-х годов учёные считали, что источником янтаря являлась смола единственного вида деревьев, сосны Pinites succinifer Goeppert, 1836, вымершей ещё в доисторические времена. Это дерево было описано по кусочкам коры, обнаруженным в янтаре. Однако, проведённые в 1980-х годах иследования, доказали, что источником янтаря были нескольких видов растений. Недавние исследования на основании инфракрасной спектроскопии (FTIR) и анализа янтаря и смолы современных живых деревьев был сделан вывод, что они происходят от хвойных растений семейства Сциадопитисовые (Sciadopityaceae). Единственным современным представителем этого семейства является Сциадопитис мутовчатый (Sciadopitys verticillata), растущий только в Японии, однако известный в ископаемом состоянии с территории всей Евразии, и даже из Гренландии Балтийский янтарь http://ru.wikipedia.org/wiki/%D0%91%D0%B0%D0%BB%D1%82%D0%B8%D0%B9%D1%81%D0%BA%D0%B8%D0%B9_%D1%8F%D0%BD%D1%82%D0%B0%D1%80%D1%8C
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Администратор Eve: Amber: Types, Testing, Prices, Copal, and Polishing by: ospen This guide attempts to discuss amber in more depth than many wonderful guides written on basic amber authentication methods and how to spot fakes. In this guide, I’ll talk about: Baltic Amber vs. Dominican Amber Tips on Picking Amber Dealers Typical Prices Differentiating Amber from Copal The Amber vs. Copal Controversy Polishing Amber Please note that all the items shown in the right-hand panel were automatically selected by eBay. I did not choose to show these items and they may not be authentic amber pieces. Types of Amber Amber is currently mined in 2 primary regions. The Baltic area has a large industry in amber mining and production and produces roughly 90% of the amber on the market. The Dominican Republic (and the nearby Mexican Chiapas region) has a smaller production industry and produces the remaining 10% of the amber on the market. Baltic Amber Clear Baltic amber ranges in color from lemon to honey to cognac to cherry. Opaque pieces can appear from butterscotch to bony white. Baltic amber tends to be heavily treated before it is brought to market. This includes heating in oil to improve clarity, using heat to create the cherry color, burning the back to create the green color, as well as melting small amber pieces together to produce a larger piece. The appealing “sun spangles” seen in amber is not natural and is created through heating. Nevertheless, all this treated amber is considered to be authentic amber. In general, amber pieces that are creamy/buttery/white and opaque or contain sun spangles can be identified to be Baltic amber. Dominican Amber Dominican (and Mexican Chiapas) amber tends to be more clear and more likely to contain fossils than Baltic amber. This amber ranges again from lemon to honey to cognac to cherry. The red amber from this region is naturally red and not treated like Baltic cherry amber. In general, Dominican amber is more fluorescent under UV than Baltic amber. Dominican amber also tends to be untreated when it comes to market. You won’t see Dominican amber with “sun spangles”. A rare type of fluorescent amber is found in this region (and only this region). It is typically called green or blue amber. The blue or green is actually a reflected color, and thus, it is possible to have a cognac piece that fluoresces blue. Light that passes through the amber piece (for example, by holding the piece against a light source) retains the amber’s actual color. In other words, the refracted and reflected colors of this type of amber are independent of each other. Blue amber that is clear tends to reflect a paler, watery blue because it is easier for light to bounce through the amber. Blue amber that has many inclusions usually fluoresces a very royal or even cobalt blue. Clear blue amber can look more blue if you put it against a black background and in a sense this is why blue amber with many inclusions looks more blue to begin with (because less light is refracted). Note that it is very difficult to take photographs of blue amber that represent how they look in real life because the exposure length can greatly enhance the blue or green flourescence. This usually isn't done intentionally by sellers and is an artifact of photography, but it is important to keep in mind that a blue amber piece usually does not look as blue as it does in the photo. Tips on Picking Amber Dealers Here are some basics tips on picking amber dealers to avoid fakes: If you see a scorpion or a frog or a lizard in a clear piece of amber, it is most likely a fake. If it were real, it would sell for a significant sum of money. If the seller is located in China, it is most likely a fake. Although, there do seem to be a small number of real blue amber sellers from Taiwan. Beware of sellers who have many products with the same shapes and uniform coloration. For example, a string of heart-shaped amber beads of very consistent coloring. This is difficult to produce with real amber due to natural variations in size and color, but easy to produce with plastic. Buy from dealers who clearly state the origin of the amber or are located in the Baltic area (Lithuania is common), the Dominican Republic, or in Mexico. Check other amber products by the seller. Authentic amber dealers have a wide range of low to high quality goods typically and many also offer amber rough. Typical Prices Here are some price ranges (in dollars per gram) for amber pieces that haven’t been set as jewelry yet. Amber pieces with insect inclusions are not included in this price list because in those cases, the rarity of the inclusion determines the price. Also keep in mind that round beads are more expensive compared with other shapes because much material has to be removed (i.e., goes to waste) to create the shape. 0.50 - 1.00: Mid-grade amber rough (with moderate amounts of inclusions) 1.00 - 2.00: High-grade amber rough (with low amounts or no inclusions) 1.00 - 2.00: Average, mid-grade amber pieces (polished pendant shapes, polished specimens). 2.00 - 8.00: High-quality amber pieces. Usually have high clarity, consistent color, good form, or carved/faceted. 4.00 - 5.00: Blue/Green amber rough. 9.00 - 12.00: Average quality polished blue amber pieces. 12.00 - 20.00: High quality polished blue amber pieces. High clarity, consistent color, very fluorescent, good form, or carved/faceted. Differentiating Amber and Copal Copal is resin that hasn’t matured to the amber stage. Amber can be between 15 to 300 million years old. The oldest dated copal, found in Japan, is only 33,000 years old. There are many common tests used to authenticate amber, however, many of these tests cannot differentiate amber from copal. For example: Both amber and copal will smell resinous when rubbed vigorously against cloth or denim. Both will float in water saturated with salt. And the UV test is ambiguous at best. Some Baltic amber barely fluoresces and many copal pieces will fluoresce mildly. Both will not have a bitter taste if you taste it with your tongue. The tests that do differentiate amber from copal are as follow: Copal is less mature than amber and is softer. Try to scratch the piece with your thumbnail as hard as you can. Amber cannot be scratched with the thumbnail and you’ll leave behind a faint trail of your nail residue which can be wiped away with cloth easily. On copal, you’ll leave behind a scratch that can’t be wiped away with cloth. Copal is more susceptible to solvents than amber. Dip a cotton swab in alcohol (or acetone) and dab the specimen. Wait 10 seconds and then wipe the alcohol off with a piece of cloth. Copal becomes tacky and the surface becomes marred. Amber will be unaffected. The Amber vs. Copal Controversy Some amber sellers will try to capitalize on the amber vs. copal “controversy” and either sell copal as amber or say that there is no difference between the two—that copal is just young amber. The fact of the matter is that there is an academic debate about the difference between copal and amber, but like in all academic disciplines, experts seldom agree with each other on everything. The argument arises due to the difficulty in accurately dating fossilized resin (since resin, in and of itself, cannot be carbon-dated) and due to the fact that the change from resin to copal to amber is a slow gradual process (influenced by geological factors) with no magical cut-off points. This is why some academics say that the copal/amber distinction is arbitrary. On the other hand, this is the typical process that all gemstones go through. Graphite doesn’t magically become diamond one day. It’s also a gradual process and is also influenced by geological factors. This doesn’t mean that we can’t tell the difference between graphite and diamond. Moreover, there are some very easy tests to determine whether fossilized resin has sufficiently matured. In other words, copal is "young amber" only in the same sense that graphite is "young diamond". Polishing Amber Manual Polishing Due to its relative softness compared with most mineral gemstones, amber is fairly easy to polish by hand if you don’t have access to industrial lapidary machines. To polish amber by hand, use successively finer grit sandpaper with foamed backing. This polishing should be done with wet/dry sandpaper and you should polish the amber wet. As you polish, you will see an amber paste from the grinding. Rinse this out frequently. Start with a coarse 80-200 grit sandpaper and remove all the crust and rind. Shape the piece as best as you can to the desired form. Then use 400 grit sandpaper to sand over the piece and make sure you have removed all the visible scratches from the coarse grit before moving on. Use a 600-800 grit next. And finish with a 1000-1400 grit sandpaper. Many sandpaper manufacturers create packs of sandpaper for car polishing that will have the right combinations. For the final polish, dab toothpaste on a piece of denim, felt, or cloth. Paste types work much better than gel types. Use pastes with the minimum amount of chemicals added (i.e., don’t use something with hydrogen peroxide for teeth whitening). Rub the piece vigorously with the paste. You should rub vigorously enough such that the piece warms a bit from the friction. Rinse the piece under water and dry it to see the polish. If desired, you can also use carnauba wax (or car wax polish) to cover up any minor scratches. Dremel Polishing The dremel can be used for shaping, carving, and polishing amber. The most important thing to keep in mind with powertools is that you have to be constantly moving the bit on the amber. Don't hold the bit in one place otherwise you will create grooves and uneven surfaces. Hold the dremel firmly and move the bit over the surface in fluid motions to smooth it. You should always be wearing protective eyewear and have a dust mask on to avoid breathing in the amber dust. You should also do the polishing near a water source (but of course, avoid wetting the dremel itself) You should constantly be rinsing the amber and the dremel tool bit to avoid overheating the amber, although it's not necessary to hold the amber under water as the drilling/sanding happens. You should sand/drill in 5-10 second intervals and then do a rinse. Use a low rotation speed (somewhere in the 10k - 15k range) to avoid overheating the amber when polishing. If you're carving away a small section to improve clarity or creating a contour, it is usually easier to hold the dremel still and use your other hand to move the amber against the tool bit. Because the amber pieve is usually smaller, it tends to be easier to move the amber to create a curved contoured section than the other way around. Practice on a piece you don't like first. For shaping, use sanding accessories (such as the sandpaper cylinders). You will probably still need to do a bit of manual polishing with finer grit sandpapers because the dremel accessories don't have fine grit sandpapers. For the final polishing, use the felt circle with a bit of toothpaste (or the polishing compound that comes with the Dremel kits) and water. Always make sure the felt circle is a little damp when polishing. It is easy to overheat and mar the amber otherwise. Guide ID: 10000000007997431 Guide created: 07/16/08 (updated 04/26/11) http://reviews.ebay.com/Amber-Types-Testing-Prices-Copal-and-Polishing_W0QQugidZ10000000007997431 More http://reviews.ebay.com/The-Truth-about-AMBER_W0QQugidZ10000000000718039
Администратор Eve: Copal – A substitute for amber Filed under:Amber Copal is frequently mistaken for amber, and it actually is amber – immature amber that is. Both amber and copal are derived from plant resin or sap that has hardened and fossilized in one form or the other. The age of amber usually ranges from 30-90 million years old, but copal is much, much younger; many specimens are only a few hundred years old. The oldest copal is only believed to be around 1 million years old, but there exists a lot of disagreement among gemologists on this. I have a beautiful copal specimen that I’ve kept all these years. Copal often has many foreign inclusions in them, these can be plant debris or insects trapped within. Since amber is more expensive than copal and many fine specimens with preserved fossilized life forms have already been collected by avid collectors, copal can be a fine (cheaper) substitute for amber. The resin that constitutes copal is mainly derived from tropical/subtropical trees like araucaria and agathis species; it is probable that deposits may exist in the tropical/subtropical forests of Asia although most of the copal is currently sourced from Colombia. My copal has quite a few termites trapped inside it and marvelously preserved I must say. It originates from Colombia (as most copal sold commercially now comes from there) and is very soft, with a probable hardness of less than 3 on the Mohs scale. But the color is fantastic, and it exudes a warm glow. You can see it from the photo I took below. >my-copal In many cases, the color of copal is actually more vivid than amber, and being more common, it is often passed off fraudulently as amber. A simple test to differentiate between copal and amber is to drip a few drops of alcohol onto the surface; copal will turn sticky while amber remains inert. Copal is not as hard as amber, and therefore tarnishes or scratches easily. If you intend to use or carry it frequently, you should use opaque specimens. It is soothing in quality, and stimulates the crown chakra and while cleansing the aura of energy blockages. It also helps to amplify the energy fields if worn around the body. If amber jewelry is too costly, copal can be worn as a substitute. If burnt, copal emits a soothing fragrance like amber, and it is sought after as incense by some alternative healers. Like amber, copal is great for making an elixir. The elixir is believed to stimulate the body’s healing mechanisms and cellular renewal. It is also good for the kidneys, bladder, prostrate and adrenal glands. Copal also assists in digestion and assimilation. While not as old as amber, it is still valuable for sharing many of amber’s characteristics and is a worthy substitute. http://www.crystalsgems.com/amber/copal-a-substitute-for-amber/
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