Glass examinations typically arise due to burglaries or hit and run crashes. Small glass particles, not readily seen by the naked eye, can be located on clothing or shoes and analyzed. The questioned glass samples found are compared to a known glass standard such as doors and windows, automobile windshields, mirrors and glass containers. Glass can vary in color, shape, thickness, refractive index and trace elemental content.
Glass examinations are performed using physical measurements, microscopy, glass refractive index measurement (GRIM) and x-ray fluorescence (XRF). Microspectrophotometry may be used on colored glass samples.
XRF spectrum of two glass samples showing different elemental content