Look at the luster of pearls of different origins first. The halo reflected from the surface or inside of nacre is different. As the saying goes, "gem-like" needs to be carefully tasted in combination with physical objects. Pearlescence is a unique luster, which is mainly reflected from the inner fine structure layer of pearls and produced by light diffraction. This luster can also be observed in the dark light without direct light, which is similar to observing the growth lines and inclusions inside the gem under the dark field gem microscope, reflecting that the pearlescent intensity of the pearl layer is particularly clear under the weak light irradiation. The light reflected by weak plastic is "thief bright", but the process of painting is deceptive to some extent, so it should be carefully identified.

Second, observe the surface characteristics of pearls. The number of surface defects of pearls directly affects the beauty of pearls, but there are few pearls without defects. The flaw of each pearl is different, but it is different from the birthmark of other pearls, which provides a basis for distinguishing authenticity. The surface defects of pearls are defects or stripes. When a foreign body invades between nacreous layers, a defect will be raised on the surface. Sometimes it is necessary to observe carefully with a magnifying glass of 10 times, and some banded phenomena will always be found.

Third, touching fake beads with your hands is greasy, real beads are cold, and hanging around your neck is cold.

Fourth, try to grind with teeth or two beads. As mentioned above, plastic beads will slip when grinding, but grinding pearls along the peak of teeth will have a sense of sand. If it is a good bead, this kind of sand feeling is particularly uniform, and the feeling is simply wonderful. This is because the crystals that make up the nacre are arranged in an orderly way, just like the roof panel, which is called shingle arrangement in jargon, so rubbing it will make people feel like sand.

5. When trying to burn with fire, the fake beads appear flame, the burning surface appears black smoke color, and the surface bead layer falls off, while the real beads do not see black smoke color on the burning surface, and the surface layer is intact and does not fall off.

As for the choice of pearls, first of all, it should be clear that freshwater pearls and seawater pearls belong to two different grades of goods, just like jade and jade, which cannot be compared. When choosing the same kind of beads, we should consider its color, luster and mother-of-pearl layer thickness, and consider its color, luster, mother-of-pearl layer thickness, shape defects (spots) and other factors to make our final choice.

The pigment of pearl consists of several color components. Its own pigments (such as white, cream, pink, black, etc. ). Generally, the primary colors of seawater beads are white (with yellow flavor). If the beads themselves are of good quality, manufacturers try to keep their true colors, but different nationalities have different preferences. If the beads are exported to Europe and America, they must be bleached. Among the black pearls, black is the best. Overtones (usually rose or green) are like rouge on a lady's face, fixed on her skin color. Not all pearls have overtones. The third is the rarest pigment, that is, the crystal clear color (Orient)-that is, the rainbow color on the pearl surface. Not all pearls will show this glittering and translucent luster. In fact, round cultured pearls rarely have this luster. Most of them appear in irregular shapes.

Gloss is one of the most important factors that consumers should consider, which is determined by the quality, transparency and thickness of mother-of-pearl layer. Sometimes there is a circle around the waist of pearls that looks pale and dull, which is related to the structural changes of local crystals. We should try to avoid this kind of pearl. There is no doubt that the stronger the luster, the better the quality.

The thicker the mother-of-pearl layer, the better. We can carefully observe the thickness of pearl layer from the perforation of pearl, and by the way, observe whether the pearl core is damaged during perforation. The thickness of bead layer can also be judged indirectly from the strength of pearlescent. Beads that are too thin are not durable, and the ideal beads should be more than half a millimeter ... the place where pearls are cultured (water temperature, nutrients, etc. ) and the length of culture time are the most important determinants of thickness.

The shape of beads should be round, smooth, even and regular. But if you can buy bigger pearls at lower cost, it will add more beauty to your pearl treasure house.

In addition to protruding defects, defects can also be cracks, cracks, depressions and dark or dim spots and strips, which should be avoided as much as possible. But when you zoom in, you can always find some problems.

If you can carefully select from the above aspects, you will definitely find your favorite pearl jewelry.

Reprint "Jewelry Craft"

Silver:

There are many kinds of silver ornaments with complex colors. Silver jewelry is generally mixed with other metals to varying degrees, so how to identify silver jewelry?

(1) Check the hardness

The higher the fineness of silver jewelry, the softer the texture and the whiter and smoother the surface. Take a silver bracelet of about 60 grams as an example. If you pull it by hand, it will open and have no elasticity, and the color is about 95%. If it is a little elastic, the color is about 80% ~ 90%; If the elasticity is large, the fineness is below 70%.

(2) Look at stubble

Cut or fold silver ornaments to see the color of stubble. If the jewelry is soft, the stubble is thick and soft, slightly red, and the color is about 95%; If you bend hard by hand, the stubble is white gray or reddish, and the color is about 90%; If the hardness is large, the stubble is reddish, yellowish white or light gray, and the color is about 80%; If it is a hard bend, the stubble is reddish, yellowish, khaki and other colors, and the color is about 70%; If the stubble is red, medium and black or yellow, the color is below 60%.

(3) Silver smear test

Grind the silver ornaments on the touchstone (the same as gold inspection) and coat them with silver medicine (silver medicine is a soft mixture of silver powder and mercury), so that the color of silver medicine will be high if it is hung more, and the color will be low if it is hung less. Those without silver medicine are fakes.

(4) color identification method

Distinguish its color and authenticity with vision. High color, white, delicate, shiny, jewelry printed with manufacturers, store numbers and other signs; Low color, yellow color and rough workmanship; The fake silver jewelry is dark and not bright.

(5) Bending method

Pinch with fingers, soft and elastic, high color, easy to bend, not easy to break; The quality of the bend is hard, or barely moving, and some can't even move their fingers; The bending of silver plating or a few strokes with a hammer will crack; Fake ones can't stand bending and break easily.

(6) Throwing method

High-quality silver jewelry is relatively heavy, so it doesn't jump high when thrown on the table, and it has the sound of "poop"; Fake or poor quality is relatively light, and it bounces high when thrown on the table, making a crisp sound.

(7) Nitric acid identification method

Drop nitric acid on the file mouth of silver jewelry with a glass rod, and the dark color is brown rice, dark green or light green; Light colors are dark green or even black.

In addition, when buying silver jewelry, we should also choose the quality from the following four aspects:

(1) Look at welding. Some silver ornaments are welded, so it depends on whether the welding is clean and tidy, whether there is false welding or open welding.

(2) Look at the brightness. It requires pure electroplating color and strong brightness.

(3) Look at the veneer. Firm and upright.

(4) look at the claws. It depends on whether the claws have burrs, prick hands and scratch clothes. It is convenient to wear.

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(1) weigh it. Gold has a heavy specific gravity (19.3g/cm3, second only to platinum, and higher than other metals, so it feels heavy to hold in your hand.

(2) look at the color. Gold is a yellow metal, bright and shiny.

(3) listen to the sound. Pure gold ratio is heavy; Strong ductility, high purity, softness and low elasticity. The high-purity gold ring falls on the concrete floor or glass plate, making a silent "flapping" sound and will not rebound.

(4) Look at its hardness. Gold has little hardness. Tap the hidden part of the ornament gently with a copper key, leaving real dents and false scratches. You can also bite with your teeth. What's left is real, and what can't be bitten is fake.

(5) Chemical inspection. Gold is extremely invisible in the air, insoluble in acid and alkali, soluble in aqua regia and potassium cyanide solution; While other impurities are dissolved in the acid. When tested with 45% nitric acid, gold did not change, silver turned black and copper bubbled green.

(6) pycnometer weighing method.

(7) Identification by touchstone.