This bottle belongs to a series of intriguing 'coin' bottles carved with the two sides of the Spanish silver dollar which, along with a gold counterpart, were standard international currency in trading during the nineteenth century. Such bottles are usually of rock crystal but are also found in other types of quartz, nephrite, and, very rarely, in glass. For a discussion of these coins, see Moss, Graham, Tsang, A Treasury of Chinese Snuff Bottles, the Mary and George Bloch Collection, Vol. 2, Part 1, Hong Kong, 1998, pp. 154-157, no. 238.