Global InformationMother coin information
Mother coins (traditional Chinese: 母錢; simplified Chinese: 母钱; pinyin: mǔ qián), alternatively known as seed coins, matrix coins,[1] or model coins (樣錢),[2] were coins used during the early stages of the casting process to produce Chinese, Japanese, Korean, Ryukyuan, and Vietnamese cash coins. As cash coins were produced using sand casting mother coins were first produced to form the basis for all subsequent cash coins to be released into circulation. Under the Han dynasty in China mints started producing cash coins using bronze master moulds to solve inconsistencies in circulating coins, this only worked partially and by the sixth century mother coins were introduced to solve these inconsistencies almost completely. The Japanese adopted the usage of mother coins in the 600s and they were used to manufacture cast Japanese coins until the Meiji period. The mother coin was initially prepared by engraving a pattern with the legend of the cash coin which had to be manufactured. In the manufacturing process mother coins were used to impress the design in moulds which were made from easily worked metals such as tin and these moulds were then placed in a rectangular frame made from pear wood filled with fine wet sand, possibly mixed with clay, and enhanced with either charcoal or coal dust to allow for the molten metal to smoothly flow through, this frame would act as a layer that separates the two parts of the coin moulds. The mother coin was recovered by the people who cast the coins and was placed on top of the second frame and the aforementioned process was repeated until fifteen layers of moulds had formed based on this single mother coin. After cooling down a "coin tree" (錢樹) or long metallic stick with the freshly minted cash coins attached in the shape of "branches" would be extracted from the mould and these coins could be broken off and if necessary had their square holes chiseled clean, after this the coins were placed on a long metal rod to simultaneously remove the rough edges for hundreds of coins and then these cash coins could be strung together and enter circulation.[3][4]
The Sangpyeong Tongbo (常平通寶) cash coins were known as yeopjeon (葉錢, "leaf coins") because of the way that cash coins resembled leaves on a branch when they were being cast in the mould.[5][6]
The introduction and subsequent usage of mother coins in the casting process proved to be paramount in controlling the quality of the cash coins. Only minor differences between mother coins remained, as the carver was very skilled. If mother coins had even the slightest error than this error would be visible on every cash coin that would be produced from it, which is why mother coins with any imperfections were quickly withdrawn from the production process before impacting many coins meant for circulation. Due to the high quality control mother coins with deformities are almost never found.[7]
- ^ Cao Jin (曹晉) (2015). "Mints and Minting in Late Imperial China Technology Organisation and Problems". Academia.edu. Retrieved 29 April 2020.
- ^ "Qianpu 錢譜.". By Ulrich Theobald (Chinaknowledge – An Encyclopaedia on Chinese History, Literature and Art). 5 December 2013. Retrieved 5 August 2023.
During the Republican period (1911–1949), the Imperial Palace Museum (at that time called Guoli Beiping gugong bowuyuan 國立北平故宮博物院) published a collection of coin catalogues from the possession of the imperial palace, called Gugong Qing qianpu 故宮清錢譜. It includes the illustrations of 284 zuqian 祖錢 "progenitor coins", muqian 母錢 "mother coins" or yangqian 樣錢 "model coins" that served as the standards for official coins.
- ^ "The Manufacture of Cash Coins". Dr. Luke Roberts at the Department of History – University of California at Santa Barbara. 24 October 2003. Retrieved 2 July 2018.
- ^ Zuroku Nihon no kahei, vol.3 (Tokyo: Touyou Keizai Shinpousha, 1974), pp. 72-79. (in Japanese).
- ^ Not listed (2019). "Korean Currency". National Institute of Korean History. Retrieved 29 September 2019.
- ^ Joseph E. Boling, NLG (1988). "Korea – A Numismatic Survey. (This article has been transposed to this format from a July 1988 supplement issue included with Coin World. Its original title was: Beyond Cash – A Numismatic Survey of Korea.)" (PDF). Moneta-Coins.com. Retrieved 3 October 2019.
- ^ "Basics of distinguishing Kan'ei coins". Luke Roberts at the Department of History – University of California at Santa Barbara. 24 October 2003. Retrieved 16 June 2017.