Glass
Sand and ash fused at high temperature make a material with no natural equivalent.
- When
- Known to
- ± 300 years
- Era
- Bronze Age, Holocene
Glass beads appear in Mesopotamia and Egypt in the third millennium BCE and true glass vessels by around 1500 BCE, formed around a core of clay and dung since blowing has not been invented. It is enormously difficult — high temperature, fussy chemistry, and opaque results unless the ingredients are right — and it stays a luxury. Cuneiform tablets from the second millennium preserve glassmaking recipes, among the oldest technical instructions known.