Glass is fragile yet hard. It is transparent. The primary ingredient is silicates, commonly known as sand. Glass also typically includes soda ash and limestone. When exposed to high temperatures, the materials fuse. The new material is then cooled rapidly to become rigid. Glass is solid, hard, fragile and can create shards when broken; it is inert, transparent and it is recyclable. Another ingredient that can be added to glass is lead. It is recognised for the way it reflects light.
Chemicals - The ingredients to create lead glass are between 54 and 65 per cent SiO2, 13 and 15 per cent Na20 (soda ash), 18 and 38 per cent PbO (lead oxide), K2 (potash) and additional oxides. If less than 18 per cent of lead oxide is used, crystal glass is created.