Glass breaks in distinctive patterns because crack propagation follows paths of least resistance through the material’s microscopic structure while releasing stored strain energy. These predictable patterns—radial (outward from impact) and concentric (circular around impact)—result from how stress waves travel through the rigid molecular structure. The unique molecular arrangement, pre-existing microscopic flaws, glass thickness, tempering status, and edge quality all influence crack patterns. Forensic experts analyze these patterns to determine break origin, impact direction, and force applied. Different glass types produce characteristic patterns: annealed glass creates large sharp shards, tempered glass disintegrates into small cubical pieces, and laminated glass stays intact even when cracked, providing valuable information for safety investigations and crime scene analysis.
