Glass conservation and restoration.

Glass is usually the most stable of archaeological materials, but glass artifacts, and 17th-century glass in particular, can undergo complex disintegration. Ideally, glass should consist of 70-74 percent silica, 16-22 percent alkali or soda ash (sodium carbonate) or potash (potassium carbonate, usually derived from wood ash), and 5-10 percent flux (lime [calcium oxide]). Soda-lime glass…