Comparison of the magnetic properties of two subsamples of archaeological quartzite cobble (sample ID #104), reddened at one end, possibly the result of heating. (a–c) Sample ID #104_3 (unheated sample); (d–f) Sample ID #104_2d (possibly heated subsample from reddened end). a,d Normalized progressive IRM acquisition curves. b,e Hysteresis cycles. c,f Thermomagnetic curves (magnetization vs. temperature). Heating (cooling) cycles are indicated for each sample.