The specific gravity test shows that natural amber is light in texture, and the density of amber (without any inlay) is between 1.05-1. 10, so in 1: 4 salt water (1 salt, 4 water), the genuine product will float. Another useful test method is to put an unknown substance into a saturated salt solution. Amber will float in salt water, while most substances will sink. This test method is usually enough to distinguish amber from bakelite and many other plastics. Synthetic imitation amber: Bakelite (or bakelite), cellophane and even acrylic are often used to imitate amber, but its proportion is too heavy, and it will sink in saturated salt water, while real amber will float. There is a kind of plastic called polystyrene, whose specific gravity and refractive index are quite close to those of real amber. The above methods can not detect the authenticity, but there is no fragrance when rubbed, and the synthetic product will smell when synthesized. The proportion of "transparent amber" is large, the proportion of "opaque amber" (such as bone amber) is small, and the proportion of amber with insects is even smaller.
Needle burning-heating test When the needle is heated to red and scalded on the surface of amber, it will have a loose fragrance and black color, and the plastic will partially melt and stick to the needle. You can also pierce beeswax or amber with a fine needle after heating with fire, and then pull it out while it is hot. If it produces the smell of black smoke and rosin, it is real amber. If it emits white smoke and produces a plastic smell, it is a fake made of plastic. In addition, when the needle is pulled out, it will be fake amber, but the real one will not. When the small pieces are heated slowly, bakelite gives off a strong electric carbon sour taste, and celluloid gives off a camphor smell.
Ether test: Drop a small drop of ether in an imperceptible place and stay for a few minutes. If amber is corroded by ether, the ether will leave spots on its surface after volatilization. Because ether volatilizes very quickly, it is sometimes necessary to use a large drop of ether or make up this drop from time to time. Although the appearance of regenerated amber pressed with amber powder at high temperature is very close to that of natural amber, if a little ether is applied, it will feel sticky and dissolved in a few minutes. You can also test the surface with nail polish remover. Amber will not react, but Coba resin will corrode. Styrene resin and shell turpentine were soaked in ether for 5-2 minutes, and then swelled and softened.
Sound test: Amber beads that are not inlaid will make a very soft and slightly dull sound when rubbed gently in your hands. If the sound is plastic or resin, it will be crisp.
Refractive index test is also a useful indicator because amber is amorphous, isotropic, cleavage-free, polychromatic and refractive, while the refractive index of bakelite is about 1.60. The refractive index of amber generally varies, but it is usually close to 1.54, which can be as low as 1.539 and as high as 1.545.
Observation and test of bubbles Because amber is a natural fossil, it is easy to become brittle, so the jewelry industry allows some processing to make it difficult to become brittle. In this process, natural gas bubbles in amber will change due to temperature, such as expansion or bursting, thus forming internal patterns with different shapes, commonly known as crystal flowers. Crystal flowers formed in this way are usually irregular, and the bubbles contained in them are usually regular and round. Regenerated amber: It is to grind natural amber particles into powder, add some plastic raw materials, and then heat to synthesize regenerated amber. Usually, linseed oil is added to color, and then pressed into a large piece of amber under high pressure. Bubbles are often mixed in this process, but the bubbles of regenerated amber are usually crushed and grow into strips.
Friction test amber has a faint pine fragrance when rubbed. Amber that produces fragrance when rubbed is called "Xiangpo". Generally, amber only emits a strong pine fragrance when it is burned.
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. As long as you have your favorite amber with more than three colors and more than three months, no one can fool you. Amber is transparent but very moist, unlike glass, crystal and diamond. Fake amber is either transparent or opaque, and the color is fake when it dies. In addition, due to the high temperature heating during artificial production, the natural structure of amber is seriously damaged, and many "crystal flowers" that burst are mostly regular and dense circles, which are dazzling and will feel lifeless cold light. After a long period of exposure to amber, you can tell the truth by intuition.
When the needle used for hardness test is slightly inclined to stab the back of amber at an angle of 20-30 degrees (where you don't think it will hurt amber), there will be a slight sense of violence and a very fine powder residue. If it is plastic or other substances with different hardness, it will either stick, feel sticky or even stick inside.
Pure natural amber with real acid and alkali has considerable corrosion resistance to ordinary daily acid and alkali, because many amber produced in the Baltic Sea are salvaged from the sea and have been in the sea for hundreds of millions of years. If you are not resistant to acid and alkali, you may not see it for a long time.
The identification method of insects and other debris in natural insects should be three-dimensional, ecological and natural, with a sense of struggle. Some larger insects will have small bubbles exhaled by their last breath in front of their mouths! Artificial insects are treated and crushed, and natural amber with insects is extremely rare and expensive.
Identification method of beeswax The only way for international beeswax experts to judge genuine beeswax is to turn red, black or star when exposed to heat. In addition, amber crumbs are pressed to form transparent and brightly colored beeswax, and many surfaces may be artificially colored. Honey wax is opaque because it contains a lot of succinic acid. After wearing for a long time, due to body temperature, the decrease of succinic acid will gradually become transparent amber.