POWERHOUSE COLLECTION

Photograph depicting polishing buttons in revolving drums

Object No. E5182-17

This photograph depicts polishing buttons in revolving barrels as part of the manufacture of pearl buttons in a Sydney factory during the early 1930s. It is part of a didactic collection in the Museum which illustrates the complete process of manufacturing pearl buttons as it was carried out in Australia, from diving for shell to marketing the finished article. The display was acquired from The Pearlbutton Manufacturing Company Limited of Foster Street, Sydney, in 1933. Pearl divers in places such as Thursday Island, Broome and Port Darwin harvested the Golden Lip pearl shell, (Pinctada maxima), from which the buttons were made. After cutting, splitting, grinding, fashioning and hole drilling 'blanks' the resulting buttons were polished. The polishing of pearl buttons was done in two stages, mechanical and chemical. First the buttons were placed in a revolving drum, or 'rumbler' with water and a small amount of pumice powder. The drums revolved for several hours until the surface of the buttons was perfectly smooth. The chemical stage consisted of boiling the buttons in soapy water and treating them with muriatic acid and bluestone to render the lustre permanent. The buttons were then washed and given a final polish by rumbling them in a felt-lined drum, after which they were ready for grading. Buttons made from pearl shell were valued because they were durable and retained their lustre unaffected by washing. After World War 2, plastics replaced pearl shell as the preferred material for buttons. The Torres Strait supplied over half the world demand for pearl shell in the 1890s. In addition to buttons, pearl shell was used for cutlery, hair combs, jewellery, decorative objects and inlay for furniture. The Powerhouse Museum collection includes a variety of objects made from pearl shell. Kathy Hackett, Photo Librarian