This article describes a field course in Cornwall looking at mineral processing with the focus on the chemistry involved. The course was split into two parts. The first looked at tin mining based around Penzance. This involved visiting mines, hunting for mineral samples, carrying out a stream survey and visiting the Camborne School of Mines Mineral Processing Department. The second part focused on china clay extraction based around St Austell and included a visit to Wheal Martyn China Clay Museum and a china clay works.