Silex Fiberglass Windows and Doors is a privately owned firm based in Winnipeg with office, showroom and fabrication facility at 1266 Border Street, and specializes in pultruded fiberglass windows and doors. Name "Silex"---Silex is the Latin word for Silica. This is the chemical compound foundation from which our window frames and glass are made from. Silica is most commonly found in nature as quartz. Silica is one of the most complex and most abundant families of materials, existing both as several minerals and being produced synthetically.