Comparative characteristics of ancient red pigments used to decorate Thracian sacred sites (4th–3rd centuries BC)

The mineral composition and geochemical features of red pigments from paints and plasters used in the color decoration of the Shushmanets, Dolno Lukovo, Maglizh tombs, the eschars from tumulus 21 and 31 from Sboryanovo National Reserve (Bulgaria) and the Documaci Tomb (Romania) are compared. The results show that red ochre pigment (mainly hematite) was applied in the decoration of all objects, and only in the Maglizh Tomb a red cinnabar pigment was used – separately or in a mixture with red ochre. Regardless of the territorial remoteness of the tombs Dolno Lukovo, Maglizh, Documaci and the eschars, the red ochres used in them contain As, Cu, Zn and inclusion of minerals jarosite, plumbojarosite and native gold. Such mineral and geochemical features are characteristic of the oxidation zones of Au-Pb-Zn deposits. The most likely source of the red ochre is the well-developed oxidation zone of Au-Pb-Zn deposits in the Eastern Rhodopes. A characteristic feature of the red ochre from the Shushmanets Tomb is the lack of heavy metals but the hematite of the ochre contains inclusions of magnetite. A probable source for mining of this pigment was non-economic magnetite-hematite ore deposits hosted in the in the neighborly exposed chlorite-sericite schists.