To what extent did materials determine value in medieval art?

To what extent did materials determine value in medieval art? Readings: C. B. McClendon, The origins of medieval architecture: building in Europe, A.D 600-900 (New Haven, Conn.; London, 2005), 105-123. PDF O. Grabar, The Dome of the Rock (Cambridge, Mass. ; London, 2006), 59-81. PDF A. Shalem, ‘The Four Faces of the Ka’ba in Mecca’, in P. Davies, D. Howard and H. Pullan, eds, Architecture and pilgrimage, 1000-1500: southern Europe and beyond (Farnham: Ashgate, 2013), 39-58 PDF R. Stalley, Early medieval architecture (Oxford, 1999), 65-67; 147-165 PDF M. Rosser Owen and G. Anderson, ‘Great Ladies and Noble Daughters: Ivories and Women in the Umayyad Court at Córdoba’, in Pearls on a String: Artists, Patrons, and Poets at the Great Islamic Courts, ed. Amy S. Landau (Baltimore and Seattle, 2015), pp. 28-51. PDF S. Guérin, ‘Exchange of Sacrifices: West Africa in the Medieval World of Goods’, The Medieval Globe, 3: 2, 2017, 97-123 E-BOOK (Log in with Senate House username and password) This is the essay question and some readings