Three different Vietnamese cash coins from the 19th century. China had had a strong influence over Vietnam for many centuries and the Vietnamese imperial court issued cash coins of the Chinese type, made by casting. The inscriptions use Chinese characters and are arranged in the Chinese way with the ruler's name vertically and the statement "Tong Bao" ("circulating treasure") horizontally. Most Vietnamese cash coins are made of copper alloys, but some are made from zinc (the northern parts of Vietnam have rich zinc deposits). Coins are denominated in cash ("van" in Vietnamese) and can have the value 1 cash/van, 10 cash/van, etc. 1 van, emperor Tu Dúc, 1848-1868. Copper alloy, cast. Weight 2.4 g, diameter 22 mm. 1 van, emperor Tu Dúc, 1848-1871. Zinc, cast. Weight 2.3 g, diameter 24 mm. 10 van, emperor Thành Thái, 1888-1907. The reverse states the value 10 van in Chinese characters. Copper alloy, cast. Weight 4.4 g, diameter 27 mm. See images for correct impression.