Urgently needed

In a study of an archaeological artefact thought to be a mask of Coptic Egyptian origin, a fragment was inspected using powder X-ray micro-diffraction to explore the possibility of identifying pigments and/or fillers in the paintwork applied to the surface of the mask. X-Ray diffraction data were collected with a Bruker D8 Discover diffractometer with CuK radiation (=1.5406A ) operating in parallel beam geometry collimated to 2mm. Data were collected were collected from three separate s for each 0.02 increment. The fragment studied is shown in the Figure below. Its surface is uneven and the fabric coating appears to be composed of a blue-green upper layer above a white, grainy sub-layer. Preliminary XRF studies have identified the presence of copper, calcium and silicon (a) Briefly explain the terms microdiffraction and why parallel beam geometry might be an advantageous choice in the analysis of the uneven surface of the sample. Illustrate your answer with a suitable diagram. (5 marks) (b) ASCII 'xy' data files from the experiment are provided on the module Blackboard. Provide a short report for the study comprised of the following components: (i) A plot of intensity vs. 2 for the data and, from this, an initial assessment of crystalline vs amorphous nature of the sample and its composition as single phase or as mixture of phases. (ii) A short description of ca. 3-5 candidate phases that might be in the coating of the fragment (consider both the pigment and its base). Briefly discuss your choice (iii) Plots of the data compared to the candidate phases from (ii) (iv) A critical evaluation of the presence of each candidate phase in the sample. (v) A brief conclusion of the study including suggestions for further work on the sample. (20 marks)