  Nine samples of ochre originating from the Sentier des Ocres near Roussillon,
France, were studied with Mossbauer spectroscopy and Spectro-photo-colorimetry.
The former yielded a quantitative phase analysis of iron containing minerals
(goethite, hematite and kaolin), and the latter enabled determination of the
CIE-L*a*b* colorimetric coefficients. Based on the results obtained it is shown
that both a* and b* coordinates are responsible for the colour of the
investigated ochres.
