Glass catches the light. It can flash crystal clear or sparkle with color. When molten, it can be shaped as no other material can: with a simple puff of air. The art of glassblowing developed in the Middle East around 100 BC. Centuries later, it reached new heights of craftsmanship under Islam. Glass blown in Baghdad and other Islamic cities traveled over the trade routes toward China, where it was treated as the rarest of jewels.
To make glass, mix three basic ingredients:
Sand: containing large amounts of silica, a hard mineral
Soda Ash: often made by burning certain plants
Lime: obtained by heating limestone
- Heat the mixture in a furnace to about 2,500 F (1,371 C), to melt the ingredients.
- Lower the temperature. Then, dip the end of a blowpipe into the molten glass.
- Blow into the pipe to form a bubble.
- Shape the bubble by rolling it against a flat surface or by pinching, pulling or cutting it with other tools.