What Makes Glass?
Glass is made using three different minerals:
- Sand (silica)
Intense heat changes sand into a fragile form of glass.
- Soda ash (sodium carbonate)
This is a powdery white material that is added to the mixture to lower the melting temperature of the sand.
- Limestone (calcium carbonate)
This is added to make the glass stronger.
The raw materials are melted together in a furnace at a temperature of 1600 C. This is the same temperature as a jet engine!
What Makes Crystal?
The inclusion of at least 24% lead oxide in the composition is required by law for crystal to be called full lead crystal. The lead lends brilliance and weight to the product. Crystal without lead is still crystal, i.e. clear glass, however, it is more commonly perceived as “glass”. The lead also make the crystal softer and more conducive to cutting. This is why the lead crystal is cut and for the most part, the unleaded crystal is not cut.