Table 2.

Selected attributes of powdered ochre used in our experiments

Sample	Munsell color	Geological type	Geographical origin	% Fe2O3	% SiO2
Synthetic Fe2O3	7.5R 4/6 red	–	–	83.9	11.8
No. 3	7.5YR 6/6 reddish yellow	Snuffbox shale	Ndwedwe quarry near Sibudu Cave	15.5	–
No. 10	10YR 7/8 yellow	″	″	21.3	13.4
No. 12	7.5 R 3/4 dusky red	″	″	56.9	10.3
No. 13	10R 4/4 weak red	″	″	51.4	–
No. 15	7.5R 4/6 red	Hematite	Waterberg	57.6	33.7

Fe and Si readings were obtained by ICP-OES, except for no. 15, which was obtained by X-ray fluorescence.