QING: Dao Guang, 1821-1850, AE cash (4.51g), Board of Works Mint, Peking, H-22.597s, Old branch mint, type B, cast 1824-50, mu qián (mother or seed coin), with crisp and well-defined characters and smooth rims and surfaces! EF, ex K.K. Lee Collection, in old American Missionary Church Tithe & Offering Envelope dated July 1, 1923. 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. Qing dynasty mother pieces are typically made with refined materials and high relief and hence have great eye-appealing appearance.