How to identify true and false red corals?

Longitudinal view: coral has parallel growth lines in the longitudinal direction, and the direction is parallel coral cylinder. If it is torus, the growth line is generally on the back; If it is a sculpture, you can see on the surface that red coral is the best among corals, and its surface color is more gratifying, and its texture is bright and moist.

Cross-sectional view: Red coral has growth lines like annual rings, which are concentric from small to large, and can generally be seen on coral ornaments.

Look at the color: the color of red coral is from the inside out. The closer the coral column is to the surface, the darker the color and the lighter the inner layer. In other words, the color of coral is uneven, and if the inside and outside colors are the same, it is suspected to be an imitation.

There are many ways to know the authenticity of red coral, including the following:

1. Coral ornaments made of sea willow and sea bamboo. The surface of this imitation has obvious longitudinal texture, uniform color and no pore characteristics unique to coral.

Second, fill in coral dyeing. Dendritic reef-building coral with loose texture in shallow sea is disguised as coral by filling and dyeing with glue. This kind of imitation has a smooth, rough and fragile surface, and its color is easy to fade and identify.

Third, synthetic coral dyeing. That is, all kinds of shellfish or reef-building corals are ground into powder and then molded into the shapes of various corals. This kind of fake coral has no natural texture, almost every coral is the same, and its color is easy to fade.

Four, all kinds of jade coral products, such as dolomite or calcite dyeing. It looks uniform in color, but it is easy to fade and dull.

Five, plastic products dyed fake coral. This kind of fake red coral is light in texture, easy to fade, without any natural texture and luster, and has no coral charm at all.

The color of coral mainly depends on its growing environment. For example, white corals are distributed in the South China Sea, the Philippine Sea, the Penghu Sea, the Sulphur Sea and the west coast of Kyushu, with white, gray, milky white and China white, which are generally used in bonsai crafts. Red corals are mainly distributed in the Pacific Ocean. They are often light to dark red to orange red, sometimes flesh red, and are generally used for setting jewelry. Blue coral was once found on the west coast of Africa, and now it is basically extinct. Because of the bright colors and the scarcity of large coral, some unscrupulous businessmen will make huge profits by counterfeiting. Generally, there are two types of forgery:

The first type: using coral-like substances to make imitation red corals. Mainly includes:

Dyed bones imitate red corals-usually by dyeing or coating animal bones such as cattle bones and elephant bones. , can be distinguished according to their own characteristics. Coral cross section has radial and concentric structure; The longitudinal section has continuous wavy texture; Bone products have intermittent straight grain texture, and corals also have the characteristics of white heart and white spots. Their color characteristics are also different. Coral red is naturally produced, and the whole body is the same color. The dyed bone imitation red coral is different in color, it will fade or become lighter, the coating surface will fall off, and the hole will turn white.

Dyed marble imitates red coral-dyed marble has a granular structure and its hardness is much higher than that of coral. It seems that the surface is highly reflective and feels bright, and it will slip when scratched with your fingers. If conditions permit, dilute acid test can be used. The solution turned red after the reaction of dyed marble, and remained white after the reaction of red coral.

Pearl oyster imitates red coral-the color and appearance of pearl oyster are similar to coral, but the luster of pearl oyster has certain directionality and its density is higher than coral.

The second type: change the color of white or poorly colored corals;

Ordinary corals are bleached or changed to imitate red corals-usually hydrogen peroxide is used to remove the turbid color of corals, especially dead corals, otherwise they will be turbid yellow. Generally, dark corals can be bleached to get light corals, black corals can be bleached to golden yellow and dark red corals can be bleached to pink.

Dyed corals imitate red corals-the easiest way to identify them is to wipe them with a cotton swab dipped in acetone. If the cotton swab changes color, it can definitely be dyed coral color. In addition, the color of dyed coral is different, and the dye is concentrated in small cracks and particles, and the color is deep outside and light inside, which is uneven. Dyed corals are easy to fade or lose luster after wearing.

The above are some simple methods to identify pearls and corals, as well as some traditional empirical methods, which can only be used as reference for identification. It is very difficult for inexperienced consumers to distinguish its authenticity. Therefore, it is suggested to buy jewelry with appraisal certificate as much as possible, or send the jewelry to an authoritative testing institution for testing to ensure the quality of jewelry.