Alum industry in North Yorkshire

The alum industry in North Yorkshire was a major chemical processing industry in North Yorkshire, England between the 17th and the 19th centuries. The production of alum was suited to North Yorkshire due to the presence of the shale rock needed to make the alum sulphate which was essential as a dyeing agent until synthetic dyes became widely available in the 19th century. Production of alum in North Yorkshire peaked in 1769 with approximately 6,000 tonnes (6,600 tons) produced. The alum industry in North Yorkshire has been labelled the first of the dirty industries in the area, with ironstone mining, steelmaking and the broader Teesside chemical industry all following on much later from the alum workings. Apart from one large site in Lancashire, almost all of the industrial alum supplied to Britain originated in North Yorkshire. Smaller concerns were operated sporadically in Dorset and London.