First, the identification of the authenticity of ivory: from the surface, real ivory can see a typical cross-ribbed grid pattern (diamond grid pattern), and the size of the grid pattern has little change (from the root to the tip, the diamond grid pattern is from large to small). Furthermore, from the inner layer of ivory, there will be concentric growth lines similar to trees, but this identification feature is only effective when identifying raw materials. In addition, ivory has a typical milky white, and ordinary bone powder pressed products are mostly miserable white. The quality of ivory is as follows: the finer the structure, the whiter the color, and the better the ivory near the cusp (the ivory at the cusp has the finest texture)

First, observe the color and fracture line of ivory itself. The skin carved by ivory will age. After a long time, the surface began to yellow, and then gradually changed from light yellow to turmeric and dark yellow until light brown. Moreover, the color of the same ivory vessel is often different. With the change of color, short hairs and silky shallow lines will appear on the surface of some objects, which we call "sparrow silk". The longer the dental instrument, the more birds, the darker and longer the color, and then cracks will appear. What counterfeiters make are all old ivory objects, the skin is colored but dull, there is no patina, and the crack of sparrow silk is unnatural. Smell it, there is a choking smell of smoke.

Second, from the artistic style of sculpture. For example, the Guanyin statue carved in the early Qing Dynasty has simple lines and the legacy of tooth carving in the Ming Dynasty. Because of the combination of deep and shallow knife techniques, it is round and straight, and the garment line is drooping and calm, giving people a sense of calm. Modern imitation Guanyin image has complex lines, weak three-dimensional sense and weak knife method.

Third, pay attention to old materials and new sculptures. The so-called "new carving from old materials" means carving old dental appliances into "ancient famous products", or transforming a part of old dental appliances into ancient dental carvings. In this regard, we can identify it from two aspects: material and technology.

Fourth, the discrimination of monetary knowledge. With regard to the identification of money, we should not only pay attention to the counterfeiting method of "adding money later", but also be wary of passing real money off as real money, especially for famous tooth carvings with inscriptions. For example, Yu Shuo, a master of micro-carving in the late Qing Dynasty and the early Republic of China, his calligraphy is not only fresh and beautiful, but also coherent and coherent. At present, Yu Shuo's works have also been counterfeited, because they are very different from the original works because of their micro-engraving, oblique fonts, straight knives and consistent strokes.

Common counterfeiting methods of ivory carving

In the market, we often see some deliberately made old tooth carvings, the material itself is ivory, but the new ivory, in order to pretend to be the old tooth carvings, counterfeiters use various means to make the new ivory teeth yellow, so as to obtain rich profits by counterfeiting antiques. Commonly used forgery methods are as follows:

First, soak the new ivory in strong tea water and heat it, or soak it in coffee juice for weeks or months.

2. Soak the ivory products in turpentine and expose them to the sun for three or four days.

Thirdly, the new ivory is baked and frozen alternately in the oven and freezer, so that it expands with heat and contracts with cold to produce cracks, pretending to be the natural cracks of the old ivory.

4. Smoked in smoke to make the color of new ivory similar to that of old ivory. After smoking, some volatile tar-like substances are evenly attached to the surface of new ivory. However, if this method is used for counterfeiting, its color can be wiped off with a cloth stained with organic solvents such as gasoline or alcohol, and the new ivory will still retain its original natural color after being erased by the false color. Sometimes, pseudo color can be washed off with warm water and soap. Dyeing with dyes was popular in the Republic of China to achieve the purpose of aging. The overall color of dyed ivory is uniform, however, the color of ivory that naturally ages with age, the most exposed part, appears darker.

Therefore, when identifying the color of teeth, we can look at the bottom or inside of teeth to see whether the change degree of color aging is consistent with the surface. Generally, it is impossible to make the color of the surface of the artificially dyed ivory different from that of the deep inside, but the natural old ivory is different in this respect, which provides a sign for us to distinguish whether the ivory is naturally yellowed or artificially made.

Ivory jewelry is expensive, so it should be distinguished from bone carving jewelry when purchasing. The following is a simple identification method:

(1) Check by weight

Jewelry of the same size, tooth carving is heavier than bone carving.

(2) Differentiate from bone.

Ivory is fine in texture and has tiny ripples on it; The texture of the bone is very rough, and the lines on it are very thick. Ivory products are oily and shiny; Bone products look very dry.

(3) Process identification

Ivory jewelry is finely crafted, while bone carving jewelry is generally rough.

(4) from the color point of view

Tooth carving jewelry is often ivory white, while bone carving jewelry is mostly bleached. Even if some tooth carving jewelry is bleached, it gives people a feeling of oily white, while bone carving jewelry looks dry after bleaching.

Some people use plastic to imitate ivory products, which can be distinguished from the lines, and there are often traces of mold on them. The following two methods can be used to identify true and false ivory, and ivory products and bone products can also be distinguished. Real ivory has some exquisite patterns. If you soak in vinegar all night, it will be as soft as rotten. Fine craftsmanship can be made at will. After the production is completed, it will be as hard as ever after being cooked in equisetum water. Without these features, it means it is not real ivory. Another way is to cook ivory with gravy, which will naturally soften. To restore its hardness, you can use the first method. The composition of ivory is basically the same as that of other animals' teeth, and it is called ivory. Its composition is close to hydroxyapatite, accounting for about 65%, and the other 35% is organic, consisting of calcium phosphate and organic matter. The hardness is about 2.5 to 2.75, the relative density is about 1.70 to 1.90 and the average refractive index is 1.535. Ivory is milky white at first, translucent and shiny, and gradually turns yellow or brown after a long time. In dark places, it has white to blue fluorescence under ultraviolet irradiation. Ivory material is expensive and has few sources, and its pure and moist characteristics are favored, so it is inevitable that counterfeit products will appear or be carved with ivory-like materials to confuse the real. Although fake ivory products are rampant, it is not difficult to distinguish the authenticity of ivory as long as you master certain methods.

First of all, the biggest feature of ivory is that it can be observed in its cross-section, which can be seen with a magnifying glass of 65,438+0.5 times, and some can be seen with the naked eye, while its longitudinal section is irregular parallel wavy lines with its natural waxy luster, which is irreplaceable by any substance. Generally speaking, ivory materials are as follows:

First, dentures: they are synthesized by chemical processes and are relatively easy to identify. For example: phenolic casting resin, nitrocellulose plastic, casein plastic, etc. In terms of weight, the products with the same size are obviously heavier because of the large proportion of ivory and the light weight of dentures. From the point of view of workmanship, most real ivory products are exquisite in workmanship, and most of them are round; Dentures have poor luster, no teeth lines, and some deliberately make teeth lines, but they are rigid and dull, and almost no lines can be seen. The lines are oval, disjoint and uniform in thickness. It can't be compared with the natural herringbone pattern and net pattern of ivory. Moreover, denture products are prone to aging, yellowing and brittleness, and products often leave traces of mold.

Second, fish teeth: that is, the teeth of larger fish in the ocean, such as sea ivory and sea pig teeth. Fish teeth are much lighter than ivory, with dense vertical stripes and poor toughness. Once they are beaten, they have been exposed. Fish's teeth are also bent into crescent shapes, which are much shorter than ivory. The ivory surface is not covered with enamel and has toughness. Ivory starts from the tooth head and has a small black spot, which extends to the center of the hollow nozzle and is called the heart. There are roughly three kinds: Sun Xin, Sesame Heart and Bad Heart. Sun Xin is the best, Sesame Heart is the second, and Bad Heart is the worst. However, fish teeth are slightly hard and fragile, and there is a layer of enamel on the surface. The luster is not as soft as ivory, but extreme. Fish tooth has a heart, too. It's all in a mess. With the material and shape of fish teeth, it is impossible to carve large-scale products, mostly small and medium-sized ones. Third, bone: the difference between ivory products and bone products:

<1> From the color identification, genuine ivory products are white and natural, although they will turn yellow after a long time, but naturally turn white after soaking in bean dregs and rubbing; Even after bleaching, ivory products will have oily luster and feel moist and delicate. Most bone products are bleached, but they become dry and rough to the touch after bleaching. After polishing and waxing, it looks like ivory, but the bones are high in calcium, fragile, light in texture, loose, with tiny black spots and brown eyes. Because of the thin bone wall, it is impossible to carve bone carving products into solid large and medium-sized products.

〈2〉 From the weight identification: products of the same size, genuine ivory has dense structure and delicate texture, and its proportion is significant. Once played, it feels heavy; Bone imitations are loose in texture and have a small specific gravity, so hands and hair float lightly. Therefore, tooth carving products are heavier than bone carving products.

〈3〉 From the skeleton identification, the real ivory is fine in texture, with fishnet and herringbone lines; Boneless eyes, in contrast, the texture of bones is rough, the lines are rough, and there are bone eyes. Ivory products are oily and shiny; Bone products are dry, and the surface is covered with rough small sand spots with a magnifying glass. From this, we can judge whether it is ivory or bone products by looking at tooth lines and small sand spots.

〈4〉 Identification from workmanship: Authentic ivory products are generally fine in workmanship, exquisite and perfect; Bone carving products are generally rough in workmanship, because their materials are rough, even if they are carefully made. In addition, bone carving products are mostly oval or oblate in shape because of small materials, and the surface is uneven.

Four. Horn: generally refers to carved products such as antlers and antelope horns. These horns have skin, but they don't have the natural texture and heart of ivory. Their sex is like tiny branches. The overall color is darker and yellower than real teeth, and the hardness is more brittle than ivory. Ivory cannot be smooth and moist, and most of the carvings are small products. Because of its small shape and few features, we must pay special attention to it when recognizing it.

Secondly, the real ivory itself has some fine patterns, which are what we call fishnet patterns and human self-patterns. If it is soaked in vinegar overnight (or boiled in vinegar), it will be soft, and then the craftsman will carve it. After production, using equisetum water will become hard and hard. If it does not have these characteristics, it is certainly not a real ivory. Finally, I tell you that real ivory products contain a certain amount of water, which will release or absorb water with the change of ambient temperature, but it is not hydrophobic. If water drops drop on ivory products, the water drops have no obvious edge, and can be evenly adsorbed on the products after being wiped open by hand, and the water will not shrink; The artificial imitation is hydrophobic, that is, the water drops dripping on the artificial imitation will not be soaked, and the water trail will shrink after the water drops are spread out by hand.