Glass as seen in game.
Glass is the 9th material unlocked in industrial buildings. They are unlocked at level 19 and sell for 120 Simoleons per piece or 600 for 5. This gives it a Simoleon to minute ratio of 0.4
Production Time: 5 hours/300 minutes
They are used in: Lighting System, TV, Microwave Oven, Cupboard, Watch, Lemonade Bottles and Game Console