The criteria for identifying amber are solid texture, no crack and beautiful color. The most precious amber is highly transparent and insect-like. There are grades according to the cleanliness, shape and size of insects, and the best grade can be classified as gems. Golden yellow and yellow-red amber are the top grade. Amber with insects is used to make face stones and chest pendants, which is of great value. Amber with many cracks, soft texture, dull color or similar color to ordinary stone is of no use value. [3]
Eliminating the false and retaining the true is the main purpose of distinguishing amber from other jewels and jade. Therefore, it is particularly important to understand the characteristics of real amber and its imitations. There are several kinds of imitations: glass, plastic, resin (resin with insufficient years, such as Barker resin) and synthetic. Imitations are called imitations because they imitate some features of the real thing, and they are similar to the real thing in look, feel and feel, so inexperienced people should not think it is true.
Amber is an organic gem, which is warm and light to the touch, which makes it different from glass. Natural amber blocks float in salt water and sink in clear water. The smell of natural amber is very special-when rubbed, heated or burned, natural amber gives off a pleasant resin smell, which helps to distinguish amber. Scraping the sample surface can also help to identify-scraping the natural amber surface will produce fine powder, while scraping the plastic imitation surface will have spiral scratches. Compared with artificial resin blocks, natural amber is easier to pulverize. If there are large, rare and precious inclusions in amber, they are probably imitations. The optimized amber, including those with inclusions, has a characteristic that only the surface has bright colors, while the interior is almost colorless. Amber is very precious-if its price is much lower than the market price at that time, we should realize that it may be an imitation.
Natural amber reacts weakly with ether and various solvents, while imitations made of Coba resin react weakly with ether and acetone (nail polish remover). After a while, the surface will become dull and sticky.
Copa resin has a strong fragrance. When the hot needle touches Copa resin, it will melt and stick to the needle, forming a long "line". Products made of Coba resin will produce very small and deep hairlike cracks when exposed to sunlight and air.
1. Experiment: Natural amber is very light. If you put it (without any inlay) in water, it will sink to the bottom. But you don't have to worry. When you add dissolved brine to it, when the salt concentration is greater than 1 4 (1 salt, 4 parts water), the real amber will float slowly, but the fake amber will not.
2. Sound: Amber chains or beads that are not inlaid will make a soft and slightly dull sound when gently rubbed in your hands. If the sound of plastic or resin is crisp.
Hupo ornaments
3. Incense: Amber rough stone that has not been finely polished can smell a faint and special aroma after being rubbed by hand to generate heat. The fragrance of white beeswax is slightly heavier than other ordinary amber, so it is called "Xiangpo". Generally speaking, amber that has been polished or carved by hand smells bad when rubbed by hand.
4. Visual inspection: This is a trick to identify true and false amber; The texture, color depth, transparency and refractive index of true amber will change with the observation angle and illumination. This feeling can't be found in any other substance. Just as we distinguish between true and false people, for example, superb artists can create lifelike wax figures, and "confusing the false with the true" is just talk, and even the best wax figures can't escape our eyes. Amber is transparent but moist, unlike glass, crystal and diamond, which can be seen at a glance. Fake amber is either transparent or opaque, and the color is fake when it dies. Artificial fake amber is dazzling, and it will feel lifeless cold light.
5. Ultraviolet irradiation: put amber under the money detector, it will have fluorescence, light green, green, blue, white and so on. Plastic fake amber does not change color.
6. Friction with static electricity: Amber can attract small pieces of paper after rubbing on clothes.
7. Feel: Amber is a neutral gem, which is generally neither too cold nor too hot. Glass imitations will have a cold feeling.
8. Hot test: the needle is burned in an inconspicuous place of amber, with a faint pine fragrance. Bakelite and plastic smell pungent and stick to needles. Friendly reminder: Too hot will leave black spots on the amber surface, which will affect the appearance.
9. Needle-picking test with a knife: Cutting amber with a paper cutter will pulverize, resin will fall off in pieces, plastic will roll up, and glass will not be cut open. When amber is washed with a hard needle at an angle of 20 ~ 30 degrees from the horizontal line, it will have an explosive feeling and extremely fine powder residue. If it is plastic or other substances with different hardness, it will not stick, or it will feel sticky, or even stick in. Friendly reminder: this experiment will damage your jewelry. If you pick out the cut part, you can only find a professional to repair it. It is best not to do it or do it less, so as not to cause harm to amber.
10. nail polish remover: wipe the amber surface repeatedly with a cotton swab, with no obvious change. Plastics, pressure and amber have not changed, but resin and Coba butter will be corroded because they are not petrified, resulting in sticking pits. Rosin will melt slowly when it is soaked in liquid medicine. Friendly reminder: some amber has a layer of polishing substance, which will turn into white spots when wiped with drugs, but this layer of white spots can be scraped off with nail shells to expose the surface of amber, and there will be no change when rubbed with drugs. The liquid medicine still has the solubility of 18% ~ 20% for amber, and the surface may become blurred after soaking for a long time)
1 1. Observe scales: This is the most important method to identify inlaid amber. Amber usually has beautiful scales of lotus leaves, which have different feelings from different angles, have different refraction and emit spiritual light. The transparency of fake amber is generally not high, and the scales emit dead light, which is similar from different angles and lacks the aura of amber. The scales and patterns in fake amber are mostly injection molded, so most of them are the same. The most common one on the market is the red scale. 12. Eyeballs: Most of the bubbles in amber are round, while most of the bubbles in pressed amber are long and flat.
12. Cost appraisal: Take it to CMA Jewelry Appraisal Center to measure refractive index, density, etc.
Myanmar amber Liuqingpo 25mm bracelet
The best test methods: visual inspection, hand feeling and salt water. Even if other methods are more or less true, they will do some harm to amber. The above identification methods cannot be used alone, and multiple test methods are used for layer-by-layer separation.
Note: There are also recycled amber in the market, also called pressed amber and melted amber. Amber is a complete amber original stone, but the recovered amber is sintered into large pieces with processed amber scraps or too small raw materials at appropriate temperature and pressure. The difference of this kind of amber is that it is similar to syrup-like stirring structure, and it is similar to "bloodshot" structure after amplification.
Chemical identification
(1) amber flammable, emitting a little black smoke, emitting white smoke when it is just extinguished, with a slight pine fragrance. When coal burns, it emits black smoke. When it is extinguished, it emits white smoke, which smells like kerosene.
(2) Spectral determination: amber 1g and rosin 1ml were respectively soaked in 10ml petroleum ether (60-90℃) for 4 hours, filtered, and the filtrate was diluted with petroleum ether to per 1- 1mg, and used for Shimadzu UV200.
(3)X-ray diffraction analysis shows that amber is amorphous, so there is no X-ray diffraction reflection.
(4) The differential thermal analysis (DTA) curve of amber has no clear peaks, valleys and defocus, which is more complicated than that of coal amber: endothermic 100 ~ 1 10℃ (small and wide), 370℃ (small) and 5 15℃. It started at about 50℃ and suddenly lost weight at 480℃, accounting for 85% of the sample weight. From 480℃ to 750℃, the weight loss is slow, accounting for 25% of the sample. That is, it volatilizes when heated and completely volatilizes at high temperature (-800℃).
The characteristics of thermal analysis curve of coal are as follows: the heat absorption is 390℃ double valley (middle) and 465℃ (middle); The exothermic curves are 493℃ (small) and 605℃ (medium); There are three stages of weightlessness, namely, between double valleys at 390℃, between sharp valleys at 465℃ and between 456 ~ 605℃. These characteristics are related to its carbon: hydrogen: oxygen ratio.