Three Samples of Raw Gypsum Spar
One of the main ingredients in Egyptian stucco is gypsum, a soft mineral composed of calcium sulfate dihydrate. In its raw form, gypsum features spearlike projections, which were later refined to facilitate casting, carving, and construction. In Egypt, these deposits originate from the Sinai Peninsula, which still acts as a source of commercial stucco products today. Upon adding water, an artisan can manipulate plaster via molding or carving. Once dried, the material hardens and sets to form. Microscopic examination highlighted how Egyptian artisans mixed their gypsum with clay or brick, which gave their stucco a highly heterogeneous composition. Whether a method of recycling ceramics or an aesthetic choice (or some combination thereof), the final carved product took on a distinctive textured appearance that juxtaposed the wooden lattices often paired with these windows.
Aga Khan Documentation Center / Wunsch Conservation Lab, MIT Libraries