What is the material of this coin? What's its name and how much is it worth?

Daquan50 "Daquan50" has the longest circulation time and the largest casting amount in Wang Mang's new dynasty, although the casting time is only 13 years. Daquan 50 seems to have a single type, but there are many versions and rich connotations. In recent years, new varieties have appeared, especially the version with decorative patterns, auspicious words and animal patterns on the back.

[Edit this paragraph] Classification

The varieties of "Daquan50" can be divided into two categories and four kinds according to the form of currency. The officially cast Daquan 50 is about 28 mm in diameter and weighs 12 baht. 8 grams of unearthed objects. Heavy series of stolen coins weigh about 10g, and some even reach 10g. The other is Bo Xiaoquan 50, which was stolen by the people when Wang Mang abolished the treasure system in the first year of Tianfeng (AD 14) and allowed Daquan 50 to depreciate, "one yuan each, circulating in parallel with new coins". The real object is 26 mm in diameter and weighs about 3 grams. There is also a "Daquan 50" privately cast by Wang Mang during the turmoil at the end of the New Dynasty. The material weight is about 0.5g (figure 1). The above four species are heavy and heavy, with little money, and the other two are unearthed in large quantities, which are common and common varieties.

This round of money began in the period of Wang Mang. Daquan 50, with heavy wheel format, not only has the characteristics of double outline, but also has its own characters: its word "big" is like a swallow, like a swallow's head is composed of two lines, and it extends downward like a flying wing and like a swallow's tail; The top of the word "Spring" is wavy (non-heavy cargo is generally flat) and looks like a "mountain". Stamp, draw the outline of fake money, endless words.

Speaking of the characteristics of the heavy ship "Daquan 50", we should also pay attention to the fact that there are similar money in the money, and the characters do not have the characteristics of heavy ship money. The so-called frontal wheel, that is, the outline of money has two layers: the outer high and the inner low, but these two wheels are not as standard as heavy wheels, and the valley is flat and shallow. Most of the forehead wheels were cast by Wang Mang in the early period of the New Dynasty, and most of the heavy wheels were cast in the later period. The forehead wheel may be the prototype of the heavy wheel.

The difficulty of surviving and finding the heavy ship "Daquan 50" is similar to that of carrying it back, but less than transferring money. The thin and small heavy wheel with a diameter of 23 mm is scarce and hard to find, and there is no open map in every catalogue. The picture shows the small round money collected by the author.

The format "Daquan 50" with four patterns on the back is rare and hard to find, so there are many fakes. The forger made four lines of four mouths into four lines that can be extended and crossed, just like the "five baht" back decoration of four mouths in the Eastern Han Dynasty. The pattern on the back of the genuine product may be hand-carved, the diagonal line is not on a horizontal line, and one of the lines has a large angle deviation, so its extension line cannot be a vertical reticle.

Daquan50 with four straight lines on the back is a new version discovered in recent years, which is similar to Daquan50 with four straight lines on the back, relatively rare and difficult to find. The four stripes on the back of Daquan 50 are from the intersection of the two sides of the inner contour to the contour, while the four straight stripes are from the center of the inner contour to the contour. This format of "Daquan 50" is a thin and small coin in the middle and late period of Wang Mang's "Ten Thousand Pieces as One", mostly unearthed in Sichuan.

Similar to the "Daquan 50" coin with four straight lines, in recent years, it has also been found that a pattern format with the back "D" is extremely rare. Similar to the "D" pattern layout, in recent years, it has been found that the "Daquan 50" with regular patterns on the back is also rare and difficult to find. Custom ornamentation was popular in the Western Han Dynasty, and it was one of the commonly used ornamentation of bronze mirrors in the Western Han Dynasty.

Similar to the "Daquan 50" with regular patterns, a pattern with the word "Dan" on the back was recently discovered. The inner profile and the lower half of the outer profile of the money back are connected by four lines to form the word "Dan". I don't know what this decoration means.

In recent years, it has also been found that the layout of Daquan 50 has four patterns: face, back, face and back. There are four patterns on the front and back, which are said to be mostly unearthed in Yunnan and very rare in the Central Plains. It is difficult to find text in this format because it is very long.