In 1870 North Carolina's mica mines were reopened, and they produce the best grade of sheet mica for glazing and a large percentage of the country's yield of this mineral.
About 1350 considerable quantities of colourless flat glass were supplied by John Alemayn of Chiddingfold for glazing the windows in St George's chapel, Windsor, and in the chapel of St Stephen, Westminster.
Coarsely grained galena is used for glazing pottery, and is then known as "potters' ore" or alquifoux.
In glazing, the greater the surface of glass, and the less space occupied by rafters and astragals as well as overlaps, the greater the admission of light.
Glaze and Glass.From almost the beginning of the prehistoric age there are glazed pottery beads found in the graves: and glazing on amulets of quartz or other stones begins in the middle of the prehistoric. Apparently then glazing went together with the working of the copper ores, and probably accidental slags in the smelting gave the first idea of using glaze intentionally.
The development of glazing at the beginning of the dynasties was sudden and effective.
The latter development of glazing was in thin delicate apple-green ware with low relief designs.
It is also used for glazing pottery, in glass-making and the glazing of linen.