An assembly of glass blocks held in a structural frame comprises a plurality of glass blocks, a rectangular structural perimeter frame, a plurality of primary muntins, each said primary muntin comprising an elongate web, the primary muntins extending entirely across the structural perimeter frame, a plurality of extruded secondary muntins, and a plurality of structural rods inserted through the secondary muntins and extending entirely across the structural perimeter frame, such that the primary and secondary muntins form a matrix within the structural perimeter frame with openings for receiving the plurality of glass blocks.