This paper shows the benefit of using transmitted light microscopy together with a Z-scanning software in fractographical analyses of glass. The strength of glass is largely dependent on processes that happen at the microscale. In this research, 52 plates were fractured in a biaxial tensile test. These were divided into five categories according to their fracture pattern. 6 plates were examined with a polarised light microscope and photographed with the Z-axis scanning function. This revealed fracture markings that are barely visible with the naked eye and overlooked when only performing a microscopic analysis of the fracture surface. This led to the conclusion that transmitted light microscopy on glass’ fracture pattern is a valuable addition in glass fractography. It gives the researcher an overview of all fracture markings and flaws in one image. This can be used as a guide to find the fracture origin and it gives new information on the crack propagation and local failure processes.