Related Clues:
- Colourless mineral used to make glass
- Proctor-___ (kitchen appliance brand)
- Big name in coffeemakers
- Proctor ___ (appliance maker)
- Crystal in some watches
- Sand ingredient
- Silicon mineral
- Mineral - at least half a gallon it's said
- Glass, its capacity unknown
- Colourless/white mineral
- Glassy mineral
- Rock-forming mineral
- Hard silica mineral
- Glossy mineral
- Amethyst or citrine