Fractal analysis in drill-cores and trenches in the gold potential area of the La Codesera in Extremadura, Spain, have demonstrated that the vein thickness generally follows a power-law distribution in the relationship N(t)=Ct-(D), where N(t) is the number of veins with a thickness greater than t.This may be interpreted in terms of the self-affine scaling of vein geometry. Gold bearing veins show lower D values than barren veins and high C values have higher overall grades