For other examples of the so-called 'peanut' group see Hugh Moss, Chinese Snuff Bottles of the Silica or Quartz Group, pp. 59-61, figs. 153-161, where the author states "their total dissimilarity to the usual type of bottle...is due to the distinctive material which must have become available at some time during the nineteenth century, and which prompted the workshop to produce a popular line of bottles in this design"