Petrological work underpins several research projects within the Department of Geology, but is the main focus of two areas of work. Projects in this area use petrology to characterize the composition and texture of particular rocks as a means of determining their geological provenance. This is of value within the area of archaeology as it provides evidence of linkage between the find site of the stone, often as a monument or sculpture, and the area of extraction. In building stone studies it enables the history of the extraction and working of a particular lithology to be pieced together. In some instances it also supports the identification of a suitable stone for remedial conservation work. Such studies are based on hand specimen identification, and where possible study of the rock in thin section by polarizing microscope. The Museum undertakes all cutting and preparation work in-house, and staff produce high quality polished microscope slides which are suitable for scanning electron microscope and X-ray diffraction applications.