Wu Zhu
Wu Zhu () is a type of Chinese cash coin produced from the Han dynasty in 118 BC when they replaced the earlier San Zhu (三銖; "Three Zhu") cash coins, which had replaced the Ban Liang (半兩) cash coins a year prior, until they themselves were replaced by the Kaiyuan Tongbao (開元通寳) cash coins of the Tang dynasty in 621 AD. The name Wu Zhu literally means "five zhu" which is a measuring unit officially weighing about 4 grams however in reality the weights and sizes of Wu Zhu cash coins varied over the years. During the Han dynasty  a very large quantity of Wu Zhu coins were cast but their production continued under subsequent dynasties until the Sui. The production of Wu Zhu cash coins was briefly suspended by Wang Mang during the Xin dynasty but after the reestablishment of the Han dynasty, the production of Wu Zhu cash coins resumed, and continued to be manufactured long after the fall of the Eastern Han dynasty for another 500 years. Minting was definitively ended in 618 with the establishment of the Tang dynasty. Wu Zhu cash coins were cast from 118 BC to 618 AD having a span of  736 years, which is the longest for any coin in the history of the world. History. Western Han dynasty. "Wu" means "five" (5) and zhu was an ancient Chinese unit of weight equal to 100 grains of millet. A "five zhu" cash coin would weigh about 4 grams. Originally Ban Liang cash weighed 12 Zhu as a Liang (tael) was 24 Zhu, however over time the weight of Ban Liang cash coins gradually decreased so the Wu Zhu cash coins were introduced as a new standard unit (after the earlier San Zhu, or "3 Zhu" cash coins) under the reign  of Emperor Emperor Wu. The introduction of the Wu Zhu also fixed the standard exchange between bronze coins and gold as 10,000 bronze Wu Zhu cash coins would be worth 1 "Jin" of gold. The first Wu Zhu cash coins had unfiled edges but the second series issued under the reign of Emperor Wu had them filed. In 118 BC the central government of the Han dynasty ordered both the Commanderies (郡, "jùn") and the Principalities (國, "guó") to cast Wu Zhu coins, these Wu Zhu coins are referred to as "Jun Guo Wu Zhu" (郡國五銖, "jùn guó wǔ zhū ) coins which at most have a diameter 33.3 millimetres and a weight of 5.8 grams. A notable feature of Jun Guo Wu Zhu coins is that they have a rim around the square center hole of the reverse side of them, these rims were added to prevent people from scraping metal off the coins which would reduce their value. Another notable feature of these early Wu Zhu's is that they tend to have edges which are unfiled, making these cash coins to generally have rough circumferences, they are notably also heavier than later cast Wu Zhu's. In 115 	Wu Zhu
4584183	BC Emperor Wu decreed that all Wu Zhu cash coins should be cast with a value of 5 cash coins, these coins are known as Chi Ze Wu Zhu" (赤仄五銖, "chì zè wǔ zhū") or "Zhong Guan Chi Ze" (鍾官赤仄, "zhōng guān chì zè") because of their "red" or "purple" edges as they were filed which resulted in the colour of the copper being visible, another feature of these cash coins is that the "Wu" (五) character tends to be composed of some rather straight lines. Starting from the year 113 BC, the central government regained the exclusive authority to  manufacture coinage, from this point Wu Zhu cash coins started being produced by the Three Offices of Shang Lin (上林三官, "shàng lín sān guān"). These Wu Zhu coins had a nominal value of one coin as opposed to the Chi Ze Wu Zhu's which had an unrealistic nominal value of five. The majority of the Shang Lin San Guan Wu Zhu's contain a raised line above the square center hole on the obverse side of the coin. Under the reign of Emperor Xuan which lasted from 73 BC until 49 BC the Wu characters were less in size  and notably was written with slightly crooked strokes that don't extend to the horizontal lines of the top and bottom ends. A number of these Western Han dynasty Wu Zhu cash coins also displayed dots which represent "stars" and crescents which represent the moon on the interior rim of the coin as well as other symbols which were considered to be auspicious being some of the earliest examples of cash coins used as Chinese amulets and charms. In the 123 years after 118 BCE, when Wu Zhu cash coins were initially introduced, over 28 billion coins were cast for  circulation. Xin dynasty. After Wang Mang had overthrown the Han dynasty with his own Xin dynasty he wished to displace the Wu Zhu currency of the Western Han dynasty, owing, it is said, to his prejudice to the "Jin" (; literally: "gold") radical () in the character zhu () of this inscription, which was also a component part of the character Liu (劉), the family name of the rulers of the House of Han, whose descendant Wang Mang had just dethroned. He introduced a number of currency reforms which met with varying degrees of success. The first reform, in AD 7, retained the  Wu Zhu coin, but reintroduced two versions of the knife money, during a later reform the Wu Zhu cash coins were completely abolished and Wang Mang placed the death penalty on anyone who dared to circulate any Wu Zhu cash coins, but as the new currency system introduced by Wang Mang was chaotic and confusing to the people they kept secretly circulating. Chengjia. The Iron Wu Zhu's of Chengjia, which resemble the Western Han dynasty Wu Zhu coin, is attributed to Gongsun Shu, who rebelled in Sichuan in AD 25, and issued iron coins, two being equal to one  Jian Wu Wu Zhu (). Head of the "zhu" component rounded. Typical of Eastern Han Wu Zhu's. In AD 30, a ditty was sung by the youths of Sichuan: "The yellow bull! the white belly! Let Wu Zhu cash coins return". This ridiculed the tokens of Wang Mang and the iron coins of Gongsun Shu, which were withdrawn by the Eastern Han Emperor Guangwu in the 16th year of Jian Wu (AD 40). The Emperor was advised that the foundation of the wealth of a country depends on a good political economy, which was found in the good old Wu  Zhu coinage, and so reissued the Wu Zhu cash coins. Eastern Han dynasty. After the fall of the Xin dynasty the production of Wu Zhu cash coins was resumed. After the restoration of the Han dynasty the production of Wu Zhu cash coins was first resumed under Emperor Guangwu who reigned from the year 25 until 56 AD. Under the reign of the warlord Dong Zhuo (董卓) the capital of the Han dynasty was moved from Luoyang to the city of Chang'an (modern day Xi'an) where he ordered that the large Qin dynasty era bronze statues which date to the  reign of Emperor Qin Shi Huang be melted down to make small cash coins, large quantity of these Wu Zhu coins were so small that they were commonly referred to as "goose eye coins" (鵝眼錢, "é yǎn qián") or "chicken eye coins" (雞目錢, "jī mù qián") by the people. As these cash coins were so diminutive in size only left half of the wu (五) Chinese character and the right half of the zhu (銖) Chinese character fit on these coins. It is also pivotal to clarify that these cash coins are not what is referred to as "chiselled rim  coins" (鑿邊錢, "záo biān qián") where regular size Wu Zhu cash coins had their insides cut out so as to form two separate cash coins. "goose eye Wu Zhu coins" or "chicken eye Wu Zhu coins" were actually cast in this diminutive manner as evidence by the remnants of the metal sprue (or stub) from the casting process are located at the rim's five o'clock position of "goose eye" or "chicken eye Wu Zhu coins". The Three Kingdoms. The Three Kingdoms period was an era in Chinese history that lasted from 220 until 280 and was characterised by a  period of disunity following the collapse of the Eastern Han dynasty. The Kingdom of Shu Han was founded after Liu Bei seized control of the city of Chengdu, immediately after the city was taken Liu Bei had discovered that the treasury was completely empty which meant that he didn't have the funds for his military expenses, this was paired with a severe shortage of copper, this severe lack of copper was so bad that it is said that in order to manufacture cash coins even the hooks which were used to hang bed curtains were melted as the government  desperately needed the metal. cover the state's expenses Liu Bei ordered the creation of Zhi Bai Wu Zhu (直百五銖, "zhí bǎi wǔ zhū") cash coins which had a nominal value or one hundred regular cash coins. Unlike the earlier coinage of the Xin dynasty which disastrously failed due to the extreme disparage between the nominal and intrinsic values the coins of the Kingdom of Shu Han weren't as badly received due to the fact that the Wu Zhu cash coins produced by Dong Zhuo only weighed around a single gram, previously a cycle plagued Chinese governments trying to  set of a fiat coinage system where first the government issued new (fiduciary) cash coins, then the government would set values, usually the people don't accept these set values, and then finally the currency doesn't trade which causes inflation to set in and counterfeiting becomes a prominent problem. Zhi Bai Wu Zhu's are usually divided into "thin" and "thick" types depending on the thickness of the cash coin. It is also believed that the Kingdom of Shu Han under the reign of Liu Bei cast a variant of the Wu Zhu cash coin which had a rim  around the square hole that is 21.7 millimetres in diameter and has a weight of around 2.3 grams and due to this associated is known as the "Shu Wu Zhu" (蜀五銖, "shǔ wǔ zhū") cash coins, but due to later archeological findings this isn't taken with absolute certainty. In the Kingdom of Cao Wei which was established by Cao Cao in 220 it is believed that only Wu Zhu coins were cast, moulds have been found dating to this period and it is confirmed that Wu Zhu cash coins were cast from the first year of the Taihe period  (227) until the second year of Xianxi period (265). Jin dynasty and the 16 Kingdoms. Under Sima Yan China was reunited for a short period of time under the rule of the Western Jin dynasty ruled from Luoyang. The Chinese economy improved under Jin rule and although no historical records mention the production of coinage under the Jin as the quantity of old Wu Zhu cash coins from the Han Dynasty that were still in circulation would not have been sufficient it is likely that the government would've had to cast a large number of cash coins in order  to need the demand coming from the market. The Great Dictionary of Chinese Numismatics claims that Wu Zhu cash coins were being cast in the city of Chengdu in the Shu region of the Western Jin dynasty (which lies in modern-day Sichuan). After a family struggle within the Sima family caused a devastating civil war, China was so weakened that the "five barbarian tribes" from the north started conquering territories in China and established their own states starting the sixteen kingdoms period. Former Liang Kingdom. The Kingdom of Former Liang started casting Wu Zhu cash coins which have traditionally  been attributed to the Kingdom of Shu known as "Shu Wu Zhu" cash coins, some of these Wu Zhu's have been discovered in the Hexi corridor (in current day Gansu province) which lead archaeologists to believe that they may have been cast under the reign of Zhang Gui. The Northern and Southern dynasties. After the Eastern Jin dynasty fell the Northern and Southern dynasties period commenced in the year 420. In the Southern dynasties it was customary for people to remove the middle part of Wu Zhu cash coins to create two separate coins, the portion cut out of  the outer ring of the Wu Zhu is usually referred to as a "thread ring Wu Zhu" (綖環五銖, "xiàn huán wǔ zhū") while the coin cut out of the inner portion is usually referred to as "chiseled rim Wu Zhu" (鑿邊五銖, "záo biān wǔ zhū") cash coins or as "cut rim Wu Zhu" (剪輪五銖, "jiǎn lún wǔ zhū") cash coins. Private casting of cash coins also became a common practice during the Northern and Southern dynasties period which resulted in there being many extremely small, thin, and very fragile bronze cash coins that were cast by these private mints. These  cash coins are known as "goose eye" (鵝眼, "é yǎn") or "chicken eye" (雞目, "jī mù") coins. Liang dynasty. Under the reign of Emperor Wu of the Liang dynasty there were two types of Wu Zhu cash coins which were being manufactured, some had an outside while others did not have an outside rim with the Wu Zhu cash coins without an outside rim are referred to as "Female coins" (女錢, "nǚ qián"). From the year 523 onwards the government of the Liang dynasty decided to cast iron Wu Zhu cash coins due to the fact that iron was both  relatively easy and not expensive to acquire in what is today Sichuan. The iron cash coins issued by the Liang dynasty are quite distinctive from other iron cash coins as they have 4 lines that radiate outwards from each corner of the square center hole which is why they're referred to as "four corner coins" (四出錢, "sì chū qián"). As it became quite common for the people to cast iron cash coins privately based on these government issues it wasn't long before their quantities increased so drastically that it required cartloads of these iron Wu Zhu cash coins  to pay for anything, even to this day these Wu Zhu's are quite common due to the widespread private production that plagued these iron issues. After them the Taiqing Fengle (太清豐樂, "Tai Qing Prosperous and Happy") cash coin was cast under the reign of Emperor Wu, these cash coins were actually believed to be Chinese numismatic charms until recently and were named after the Taiqing period (547-549). In 552 under the reign of Emperor Yuan the capital city was moved to the city of Jiangling, the Jiangling Mint issued Wu Zhu cash coins which had two "stars" (a  term used to refer to dots on cash coins) on the observe of the Wu Zhu, one "star" was situated above the square center hole and one below and for this reason are commonly known as "Two Pillar Wu Zhu cash coins" (兩柱五銖錢, "liǎng zhù wǔ zhū qián"). These Wu Zhu's were nominally ten normal Wu Zhu's and are relatively rare today. From the year 557 under the reign of Emperor Jing had Wu Zhu cash coins produced that had one "star" above the square hole and one "star" below on both sides of these Wu Zhu's  which is why they are known as "Four Pillar Wu Zhu cash coins" (四柱五銖錢, "sì zhù wǔ zhū qián") and had a nominal value of 20 normal Wu Zhu cash coins, but merely 10 days after their introduction they were trading at par with regular Wu Zhu's. Another variant of these "Four Pillar Wu Zhu cash coins" had the "stars" on the left and right sides of the square center hole. Today "Four Pillar Wu Zhu cash coins" are extremely rare with those that have the "stars" above and below the square center hole being the rarest. Another variant  of Liang dynasty era Wu Zhu's known as the "Three Pillar Wu Zhu cash coins" (三柱五銖錢, "sān zhù wǔ zhū qián") were produced, however as no historical records mention them it is exactly unknown when they were produced, it is speculated by some Chinese numismatists and Gary Ashkenazy that they were only produced for five days in the year 557 immediately after the production of the "Four Pillar Wu Zhu cash coins" to circulate at a value of 10 normal Wu Zhu's and had three "stars" to differentiate them from the earlier "Two Pillar Wu Zhu cash coins  which had the same exaggerated nominal value. Three Pillar Wu Zhu cash coins" have one "star" above and one "star" below the obverse square hole, while they have one "star" just to the left and touching the rim that surrounds the square center hole on the reverse side of the coin. These cash coins are extremely rare today due to their extremely short production period. Note that despite their high nominal values, "Two Pillar", "Three Pillar", and "Four Pillar" Wu Zhu cash coins usually weighed less than 2 or 3 grams, this disparity between their nominal and intrinsic values was  a contributing factor to the decline of the economy of the Liang dynasty. Chen dynasty. The Chen dynasty produced Wu Zhu cash coins which had a nominal value of 10 "Goose Eye Wu Zhu's" and/or "Chicken Eye Wu Zhu's" and were known as "Tianjia Wu Zhu cash coins" (天嘉五銖錢, "tiān jiā wǔ zhū qián") because they were produced during the Tianjia period of Emperor Wen, however as not a single specimen exists today it is unknown how these Tianjia era Wu Zhu's looked like. It is speculated that these Tianjia era Wu Zhu's would have been  relatively big and had a rim around the square center hole on the observe side of the coin being overall similar to the Taihuo Liuzhu (太貨六銖, "tài huò liù zhū") cash coins. Wu Zhu cash coins that fit this description historically have been believed to have been produced during the Tianjian era (502-519) in the Liang dynasty under the reign of Emperor Wu. As Wu Zhu cash coins also fitting this description have been dug up in Guanzhong, Shaanxi it has been proposed that they might've been produced by the Northern Zhou dynasty. Under the reign of Emperor  Xuan in 579 the Taihuo Liuzhu (太貨六銖, "tài huò liù zhū") cash coins were cast which originally had a nominal value of 10 Wu Zhu's but due to the fact that this fact accepted by the populace its nominal value was decreased to be equal to the Wu Zhu. Taihuo Liuzhu cash coins considered to be the "crown jewel" of Southern dyansty coinage due to the quality of its calligraphy. As the seal script version of the Hanzi character for "six" (六, "liù") looked similar to a human being standing akimbo which inspired the contemporary saying that this symbolised  the general people standing in this position before the Emperor and exclaiming that the nominal value of the Taihuo Liuzhu was too high. An extremely rare version of this cash coin exists that only has the inscription Liu Zhu (六銖, "liù zhū"), this coin is in fact so rare that only a single specimen of it has ever been reported to exist. Northern Wei dynasty. The Northern Wei dynasty was a Xianbei ruled state under the Tuoba clan that adopted the administrative system of the Han Chinese and even established their capital city at Luoyang, a city which had been  the capital city of various preceding Chinese dynasties and mandated that his people adopt both Chinese fashion and language. During this period Emperor Xiaowen ordered the issuance of the Taihe Wuzhu (太和五銖, "tài hé wǔ zhū") as part of this Sinicisation process. There is one purported version of the Taihe Wuzhu which has the Chinese character "Tai" (太) written in a calligraphic style akin to that of the "Tai" on the Taihuo Liuzhu (太貨六銖, "tài huò liù zhū") cash coin issued by the Chen dynasty. However, as the only evidence relating to the existence of this cash coin comes from  rubbings in old coin catalogues it is speculated that or actually isn't real. The Northern Wei dynasty started issuing regular Wu Zhu (五銖) cash coins in 510 but it is currently unknown what special characteristics these Wu Zhu cash coins had to differentiate them from other Wu Zhu's. Emperor Xiaozhuang ordered the creation of the Yongan Wuzhu in the year 529 which was during the Yongan period (528-530), despite the fact that the authoritative power government of the Northern Wei dynasty was in trouble as the rebellion of the Six Frontier Towns waged on for a decade . After Emperor Xiaowu was forced to flee from Luoyang in the year 534 the country split into the Western Wei dynasty and the Eastern Wei dynasty, and despite the fact that neither country existed for a long period of time they both continued issuing Yongan Wuzhu cash coins to the point that both large quantities and a large number of varieties exist, as well as the fact that Yongan Wuzhu cash coins are still extremely common today. During this era various nicknames for cash coins were given by the people which include the "Auspicious cash coins" (吉錢, "jí qián") as  well as the "Heavenly Pillar" (天株) cash coins, it is unknown what these cash coins were but it's speculated by Gary Ashkenazy that they were variants of the Yongan Wuzhu cash coins, according to Gary Ashkenazy the "Auspicious cash coins" were very likely to have been Yongan Wuzhu's that had the Hanzi character for "earth" (土) on the reverse side of the coin above the square center hole. The nickname would then be derived from the fact that the square center hole resembles the Hanzi character "" and as the "土" would be above it they together would look  like "" meaning "auspicious". According to Gary Ashkenazy the "Heavenly Pillar" cash coin may have also been a variety of the Yongan Wuzhu which has a "dot" (dots represent "stars" (星) on Chinese cash coins) in the lower right part of the obverse side of the coin. When the "Heavenly Pillar" cash coin is held upright it would point towards the sky or "heaven" (天). The "star" in this particular case can also be referred to as a "pillar" (株) because it is cylindrically shaped and appears to rise up from the surface (肉) of the Yongan Wuzhu cash coin. Another  variant of the Yongan Wuzhu is also known as the "four corner" (si chu 四出) cash coin because it has 4 diagonal lines thar extend outwards from the corners of the square center hole all the way to the reverse rim of these Yongan Wuzhu coins. There were other cash coins in this era which also had descriptive nicknames assigned to them such as "Yongzhou Green-Red" (雍州青赤, "yōng zhōu qīng chì"), "Liangzhou Born Thick" (梁州生厚, "liáng zhōu shēng hòu"), "Tight Cash" (緊錢, "jǐn qián"), and "Red Halter" (赤牽, "chì qiān"). These cash coins were mentioned in historical records and  may have also been references to specific varieties of Yongan Wuzhu cash coins which currently aren't clearly identified yet. Western Wei dynasty. The Western Wei dynasty existed briefly from the year 535 until 556, historical records mention that an Wu Zhu cash coin was cast during the Datong period (535-551) which had a calligraphic style akin to that of the earlier Yongan Wuzhu cash coins as well as those of the Sui Wu Zhu's. A defining characteristic of these "Datong Wu Zhu cash coins" (大統五銖錢, "dà tǒng wǔ zhū qián") is the fact that they have a  broad outer rim with an inner rim only by the "Wu" (五) character to the right side of the square center hole. Northern Qi dynasty. The Northern Qi dynasty was a country founded by Emperor Wenxuan that existed from the year 550 until 577, from the year 553 the Changping Wuzhu (常平五銖, "chángpíng wǔ zhū") cash coins were cast. Sui dynasty. China was reunified under the Sui dynasty (581–618). Under this short-lived dynasty, many reforms were initiated that led to the subsequent success of the Tang dynasty. The only coin associated with the Sui is a Wu Zhu coin . Emperor Wen decreed that Wu Zhu cash coins be produced in the first year of the Kaihuang period (581 in the Gregorian calendar), alongside the introduction of this new Wu Zhu cash coin the older currencies were gradually being deprecated and with the conquest of the Chen dynasty the coins now known as "Sui Wu Zhu cash coins" (隋五銖錢, "suí wǔ zhū qián") were the only circulating currency in all of China. The reason why Emperor Wen introduced a new Wu Zhu was because the fiduciary cash coins of the Northern Zhou and Chen dynasties placed the economy in a  bad state and the Sui Wu Zhu's were set to the original weight of 2 grams. The first Wu Zhu's are known as the "Kaihuang Wu Zhu cash coins" (開皇五銖, "kāi huáng wǔ zhū") because of their year of introduction, later Emperor Wen allowed the principalities of the Sui dynasty to cast their own Wu Zhu's. Additional mints were set up in various prefectures, typically with five furnaces each. Cash was frequently checked for quality by the officials. However, after 605, private coining again caused a deterioration of the coinage. Today these Wu Zhu cash coins are  still very common and must have likely been manufactured in immense numbers. The fabric of the Wu Zhu's of the Sui dynasty is unlike that of any earlier Chinese cash coins but resemble that of the vast majority of later produced Chinese coins. The rims of these Wu Zhu's tend to be broad and flat, while earlier Chinese cash coins usually have thin and rather rounded rims. The basic fabric of a coin is dictated by the minting techniques used to produce it and the Wu Zhu's of the Sui dynasty were produced with an entirely new  casting technology. Among the varieties of the Sui dynasty era Wu Zhu is one which is particularly well-made composed of what the Chinese call "white copper" (白銅, "bái tóng") and are therefore known as "Bai Qian Wu Zhu" (白錢五銖, "bái qián wǔ zhū") cash coins and are believed to have been manufactured in the Jiangnan region. The Chinese character "Wu" (五) on these coins is slightly more curved where the lines cross. Wu Zhu cash coins from the Sui dynasty are known to be produced in both larger and smaller sizes, the smaller and lighter Wu Zhu's were  produced later as the country was facing higher expenditures and debased the coinage, the last Wu Zhu cash coins of the Sui dynasty circulated alongside improvised currency such as scraps of iron, paper, and leather. List of types of Wu Zhu coins. Almost nine hundred different types and over eighteen hundred varieties of Wu Zhu cash coins and Wu Zhu derivatives are known to exist. List of variants of Wu Zhu cash coins: Kingdom of Kucha. The Kingdom of Kucha was a Buddhist state located in present-day Kucha County, Xinjiang, it was first recorded during the Han dynasty and  was later annexed by the Tang, during its time it was a prominent player on the silk road. From around the third or fourth century the Kingdom of Kucha began the manufacture of Wu Zhu cash coins inspired by the diminutive and devalued Wu Zhu's of the post-Han dynasty era in Chinese history. There are five known types of Kucha cash coins based on the Chinese Wu Zhu's which are usually characterised by the fact that they're diminutive in size, very thin, and tend to have both weak and irregular inscriptions while four of these types  tend to have no inscriptions at all. One type of Kucha Wu Zhu cash coin is the "Han Gui bilingual Wu Zhu coin" (漢龜二體五銖錢, "hàn guī èr tǐ wǔ zhū qián") which are characterised by the fact that the obverse side resembles Chinese Wu Zhu coins while the reverse sides feature a local Kucha script above and below the square center hole. As the language of the Kingdom of Kucha isn't well preserved in the modern era many hypotheses have been suggested about its meaning including that it is simply a translation of "Wu Zhu" or feature the name  of the Kingdom of Kucha in the Kuśiññe language. Cash coins without any inscription cast in this region are generally believed to have been produced between the years 265 and 589, the first variant of these cash coins are round in shape and have a rim around the square centre hole on one side while the other side is rimless, they tend to thin on the outside while they're thick on the inside and weigh between 0.4 grams 1.7 grams, and have a diameter of 9 to 18 millimetres. The second type can be described as similar to the  aforementioned type but have no inner rim, these cash coins generally from 8 to 13 millimetres in diameter and have a weight of 0.2 to 0.4 grams. The third type of these cash coins are also completely without rim but are square in shape and have a square centre hole, they tend to be very thin with diameters between 8 and 11 millimetres and weigh between 0.2 and 0.5 grams. The final variant are irregularly shaped, diminutive in size, thin, and are cast of poor workmanship. Some are merely five millimetres in diameter and weigh as little as 0.2 grams . The Buddhist monk Xuanzang describes that there are "small bronze coins" in the city of Kucha while he visited there in the year 630 which is mentioned in his work "Great Tang Records on the Western Regions" during the Tang dynasty. These cash coins are likely to have been the "Han Gui bilingual Wu Zhu coin". Wu Zhu coins and the emergence of Chinese charms. Wu Zhu cash coins played a central role in the emergence of Chinese numismatic charms, as the Wu Zhu cash coins were cast in enormous quantities during both the Western Han dynasty and the subsequent  seven hundred years of its usage not all variants can be directly attributed to every ruler, however "auspicious" symbols such as stars (dots), suns (circles), moons (crescents), numbers, rod numerals, Hanzi characters, lines, and others started to be used after the Eastern Han dynasty, the reason for the earlier uniformity was the usage of bronze moulds which last for a long time, these moulds continued to be used over and over again by subsequent dynasties. However, as other techniques such as mother coins started to be used some mints started adding these "auspicious" symbols which became the inspiration for later  Chinese charms and amulets. Although the usage of some these symbols were already used on the earlier Ban Liang cash coins, they became more common on the Wu Zhu. It unclear why exactly these symbols started being added in large quantities during the Eastern Han dynasty and later but the first Chinese charms and amulets started emulating their design. Some of these early Wu Zhu coins also had the precursors to the "flower" or "rosette" holes found on later cash coins as such coins were discussed in an article in the 1987 (7th issue) of the Chinese periodical "Shaanxi Finance  (陝西金融, shǎn xī jīn róng") which shows rubbings of several Wu Zhu cash coins with unusual center holes found in a hoard. Wu Zhu charms. Chinese numismatic charms based on Wu Zhu cash coins tend to feature the same "auspicious symbolism" as contemporary Wu Zhu cash coins had themselves including crescents representing the moon, circles representing the sun, and dots representing the stars, in fact to an untrained eye Wu Zhu charms can be interchangeable with regular Wu Zhu coins. Other than these features it's also not uncommon for Wu Zhu charms to feature wholly original iconography from various  aspects of Chinese culture such as a dragon and a fisherman. Other than simply having the inscription "Wu Zhu" some Wu Zhu charms are also based on other variants of the Wu Zhu cash coins with four character inscriptions that incorporate the legend "Wu Zhu". Hoards of Wu Zhu cash coins. In the modern era hoards of Wu Zhu cash coins tend to be very common in China as these coins were produced in large quantities.