The casting technology of ancient silver ingots is an important basis for judging the authenticity of silver ingots. It is usually characterized by honeycomb and silk veins. The characteristics of silver precious metals are highlighted. However, modern industrial casting silver ingots all regard these two situations as casting defects.
Second, color.
Because the old silver ingot will be damaged by human touch and oxidation when it is used or buried underground, it has naturally formed a layer of silver rust and patina. Silver rust and patina are mostly gray or grayish brown, and the color is warm and moist. The fake ingots made of real silver can't produce natural patina like the old ingots because of their short time. Its color looks like it has just been baked, and it is very lively, especially at the bottom and sides. In order to cover up this feature, counterfeiters often coat silver ingots with a layer of chemical drugs, so that the surface of silver ingots becomes black or other colors of flower patina.
Third, weight, sound.
Before the Qing Dynasty, there was no uniform regulation on the casting weight of silver ingots, but the weights of the two kinds of silver ingots were different, such as 42g in Tang Dynasty, 39g in Song Dynasty, 36.6g in Yuan Dynasty and 37g in Ming Dynasty. If the weight collected at that time does not meet the standard, you should be vigilant.
Listening to the sound of silver ingots is mainly to prevent fake ingots from cladding. For the silver ingot in question, take another silver ingot and knock it. If there is a hollow sound or a broken sound, it should be a silver ingot.
Extended data:
The ways of forging silver ingots are mainly divided into reducing the fineness and weight of silver.
First, lead and tin are used, and their surfaces are bluish black, which is relatively easy to be recognized by collectors;
Second, when casting, the copper block is solidified in the silver ingot, and the surface is silvered, which is large and light, and the feel is obviously different; The third method is lead pouring, in which a small hole is dug at the bottom of the real silver ingot, the silver is taken out, then lead is poured in, and then the hole is sealed and welded. Careful observation shows that there are traces of sealing welding in the hole. The latter two methods need to be identified by investment experts according to their handfeel, otherwise, they will be identified with the help of precision instruments.
References:
Baidu encyclopedia-silver ingot
Baidu Encyclopedia-Silver Ingot in Ming and Qing Dynasties