This method determines tellurium at concentrations down to 001 p.p.m., with geochemical accuracy. Tellurium is volatilized from the rock at 800C in the presence of sulphur from decomposing pyrite, condensed, dissolved, and finally determined by atomic absorption in a long tube burner. The distribution of Te is shown near some gold lodes at Kalgoorlie. Lastly, a method of synthesizing Te-free pyrite from sulphur and ferrous sulphate is described.