Glass Block

Glass block, also called glass brick, is a hollow or solid architectural masonry unit made of pressed glass, typically formed from two halves fused together to create a sealed hollow cavity, laid in mortar joints like conventional brick to build translucent walls and partitions that admit daylight while obscuring clear vision through them. Developed in the late nineteenth century and popularized through the early and mid-twentieth century, notably in Art Deco and Streamline Moderne architecture, it found particular use in stairwells, bathrooms, industrial daylighting and security-conscious openings where light was wanted without a clear view or an easily broken pane. Its thermal performance, provided by the sealed air cavity in hollow units, and its resistance to impact compared with ordinary window glass have kept it in continued if niche architectural use.