The transformation of yellow goethite into red hematite by heating has long been assumed for Palaeolithic red artefacts excavated close to fireplaces. However, this transformation is extremely rare. Using SEM-FEG-EDX, PIXE-PIGE, TEM and mXRD, we characterized the mineralogical and chemical compositions of four microsamples of colouring materials from the Mousterian layer B in the es-Skhul rock-shelter, from about 100 kya ago. For some colouring materials, the Mousterian people of es-Skhul chose to gather remote yellow lumps for heating. Their significant transport distance provides evidence of the possible high cultural value of these colouring materials for transformation into red pigments.

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Analysis of archeological materials aims to rediscover the know-how of prehistoric men by determining the nature of the painting matter, its preparation mode, and the geographic origin of its raw materials. The preparation mode of the painting matter of the paleolithic rock art apparently consisted of mixing, grinding, and also heat-treatment.In this study, we focus on black pigments and more particularly manganese oxides. Using the combined approach of transmission electron microscopy (TEM) and Mn K-edge Xray absorption near-edge structure (XANES) spectroscopy, we analyzed a variety of archeological black painted samples. The studied pigments arise from the caves of Ekain (Basque country, Spain), Labastide and Gargas (Hautes-Pyrénées, France). In addition, a black "crayon" (i.e., a "pen") from the cave of Combe Saunière (Dordogne, France) was also investigated. From the analysis of these painting matters, several unusual minerals have been identified as black pigment, such as manganite, groutite, todorokite and birnessite. These conclusions enable us to estimate the technical level of paleolithic artists: they didn't use heat-treatment to prepare black painting matter. Consequently, the unusual mineralogy found in some of these pigments suggests that some of the manganese ores are coming from geological settings that are sometimes relatively far away from the Dordogne and Basque region such as in Ariège (central-oriental Pyrénées).PACS 68.37Lp; 61.10Ht; 83.80Nb IntroductionSince the recognition of rock art in 1902 in southwestern Europe [1], several questions were raised regarding the geographic (or geological) origins of the pigments, the preparation mode and the painting methods. Elemental and structural analysis were conducted to determine the mineralogical nature of these pigments: red is due to hematite The purpose of this article is to present the minerals newly identified in several archeological samples coming from various caves or sites. The rock art painting matter was sampled on two figures of the cave of Ekain (Spanish Basque country) and on two negative hands of the cave of Gargas (HautesPyrénées, France). The others samples come from natural deposits inside the cave of Labastide (Hautes-Pyrénées, France) and from black blocks (a "crayon"; or a "pen") in settlement context (Combe Saunière in Dordogne, France).