A glass factory is one of the commodity industries. In normal mode these are Indestructible.
It will produce glass on a monthly basis, and depending on the amount of quartz quarry's around.
The glass will also upgrade itself on a higher level when their balance is enough to play for the upgrade. The base upgrade time is about 8 weeks and higher production will only occur after completing the upgrade, but it will be able to still produce the normal amount.
These industries are producing:
small glass factory[]
industry type: resource production
price: 16.750.000 $
size: 4 X 3 fields
production base amount: 16
storage size: 64
normal glass factory[]
industry type: resource production
price: 35.500.000 $
size: 4 X 5 fields
production base amount: 26
storage size: 156
large glass factory[]
industry type: resource production
price: 65.000.000 $
size: 6 X 6 fields
production base amount: 44
storage size: 440