Extended Data Fig. 2: Ochre piece OP1.

a, Ochre piece OP1, numbers indicate the analyzed areas (zone 1: grey polished area; zone 2: purple granular area; zone 3: coarse-grained area; zone 4: blistered area). b, drawing of ochre piece OP1, grey areas represent flake scars. c–f, SEM images of ochre piece OP1 (zones 1 to 4 respectively): grey polished area (c); purple granular area (d); coarse-grained area (e); blistered area (f). g, µ-Raman spectra obtained from the analysis of zone 1 (grey polished area, spectrum 1) and zone 3 (coarse-grained area, spectrum 2) showing the presence of hematite (H) and quartz (Q). The hematite reference spectrum is indicated in red: RRUFF ID R110013⁹⁸. OP1 (28 x 20 mm in size; 12,4 g in mass) is a fragment of a larger nodule showing a portion of the original curved outer surface and several flake scars. The outer surface features a cracked and pitted texture alternating compact (grey polished area, zone 1 in a) and granular zones (purple granular and coarse-grained areas, zones 2 and 3 respectively in a). The flake scars feature a homogeneously blistered structure partially hidden on one surface by a yellow and on another by a dark red coating (blistered area, zone 4 in a). The blisters are smoother on some surfaces. Differential alteration indicates different episodes of fragmentation, probably due to knapping.