Last week, Ina St George visited to photograph and sample some of our most colourful minerals. As part of research for her DPhil at the Archaeology Department in the University of Oxford, she is studying the pigments used at an archaeological site in Turkey.
Our Museum’s collections include samples of the kinds of minerals used for colouring in paintings, artefacts, and body decoration, obtained from countries all around the world. Ina tells us:
“My project is looking at paintings and pigments from a Neolithic, 9,000 year old site in Turkey called Çatalhöyük. Part of the project is to characterise these pigments using techniques for mineralogical and chemical analysis. The palette of colours at my case study site has both pigments often used in prehistoric times such as iron oxides and carbonaceous blacks, and much rarer ones such as the minerals cinnabar, azurite, and malachite.
“Historically, pigment analysis, referred to as ‘technical art history’, focuses on the actual material that gives the colour, such as hematite or cinnabar. This is more appropriate for historical or modern pigments where preparation techniques and tools were more refined, allowing the artist to use grains of pure colourant.
“In prehistoric times, tools for the preparation of pigments were cruder, and so archaeological samples of pigment tend to have more of other minerals contaminating them. For instance, we see a higher proportion of quartz in a cinnabar sample, or iron minerals in an azurite or malachite sample. In my project, I will be able to see this using a microscope, looking at particles at high magnifications, and analyse the minerals using techniques such as X-ray diffraction or scanning electron microscopy.
“Seeing the minerals in the Museum of Natural History’s collection is an opportunity to better train my eye to see the source minerals for pigments, and to photograph mineralogical samples with a confirmed provenance for my D.Phil thesis.”
You can find out more about Ina’s work in her blog: www.inastgeorge.com
Monica Price, Head of Earth Collections