Contemporary Collections: Preprints from the AICCM National Conference 17th g 19th October 2007 Brisbane pp. 43-50
Abstract
Red ochre has been used as a pigment for millennia, in applications as diverse as decoration, ceremonial use and medicine, evidence of which still exists in Australian indigineous art today. Consisting largely of the iron oxide haematite, the best quality ochres were systematically quarried at a limited number of sources, including Wilgie Mia (WA), Bookartoo (SA), Karrku (WA) and Lawra (NT). Red ochres are therefore an excellent material for provenancing if these sources can be characterised by mineralogy. A large range of analytical methods were tested and applied to establishing identifiable characteristics of ochre sources. As the mineralogy of red ochres was far more complicated than simple identification of Haematite (e.g. using Raman) permits, analytical
techniques were expanded to include those capable of identifying clays (FT-IR), mineral phases (Synchrotron-XRD), and trace elements (LA-ICP/MS, PIXE/PIGME). The composition and structure of ochre specimens were established, and evaluated for possible future provenancing work. Variation in the mine itself as well as variation within the collected sample showed the need for repeated, homogeneous samples.