Fiberglass is made from thin filaments of glass. It is flexible, unlike most other forms of glass. Thin flexible glass is available from commercial vendors. It might make an interesting material for Martian greenhouses, if it proves to be fabricable on Mars.
Fiber Reinforced Polymers
Natural or synthetic polymers are often combined with fiberglass to create a strong, yet lightweight, composite material. This material is often referred to as fiberglass, though technically it is a fiber reinforced polymer (FRP).
Fiberglass can be produced on Mars from molten glass.