Sigiriya Mirror Wall lime plaster: beeswax polishing, egg-white binders, and graffiti preservation?

The 5th-century Mirror Wall (Katapath Bamma) at Sigiriya is a brick masonry parapet wall flanking the western rock terrace. Ancient plasterers achieved its porcelain-like reflective gloss through multi-layered formulation: a base coat of clay tempered with rice husks and sand was covered by an ultra-fine finish plaster composed of slaked sea-shell lime, ground feldspathic sand, egg white (albumin), and plant gums extracted from wild fig and Beli fruit. Once leather-hard, the plaster was vigorously hand-burnished using smooth chalcedony stones and treated with heated natural beeswax, producing a vitreous, non-porous glazed surface.