production of 2 mǎo (卯) of Zhiqian with the zinc-alloy cash coins because the Ministry of Revenue mint had zinc in store, which would immediately allow the mint to save 100,000 catty of copper. List of cash coins issued by the Qing dynasty Silver coinage Originally imperial China was on a monometallic standard of using only bronze cash coins during most of its history, but the large influx, because of international trade, of silver during the Ming dynasty period created a bimetallic system in China. From the 3rd century B.C. copper had been the paramount currency of most of China but during the 16th and 17th centuries A.D. this had changed. Silver had long been the currency for China's overseas trade until the mid-1930s. China during most of the Qing dynasty period was not a silver producing country and its silver supply relied on imports from abroad. It was only during the 1890s that provincial Chinese mints started producing native silver coinages. Status of silver during the Qing dynasty During the most of the Qing dynasty period silver circulated in China in two forms, that of silver sycees and foreign silver dollars (primarily Spanish dollars from Spanish Philippines). Silver was used more in interregional trade and was more often used to pay for large transactions, furthermore it wasn't counted by denomination but by weight. The primary weight unit of silver was the tael. Contrary to copper, silver was not monopolised by the government but the price of silver instead was determined by the market. The tael was used both as a unit of account as well as a unit of weight, the concept is similar to "pound" and "pound sterling". There were various standards for defining the weight of a tael, this was because the weighing scales varied a lot between the different regions of China and Qing government bodies. The weight unit "tael" (兩) usually varied between 33.99 and 37.50 grams, but when used as a unit of account the "silver tael" (銀兩) had many different definitions that were based in terms of purity and fineness of the silver being weighed. For example, the Treasury tael (Kuping liang or Kuping tael) is the standard for taxation, the Maritime Customs tael (Haiguan liang or Haikwan tael) is the standard used in the Maritime Customs Service, the market tael (Shiping liang) is the standard used in the market in Beijing. Contrary